var CurrentLanguage = parseInt("2");
var SipPort = parseInt("5060");
var RtpBasePort = parseInt("8000");
var RtpMaxPort = parseInt("8064");
var TelnetPort = parseInt("23");
var WebPort = parseInt("80");
var WebsPort = parseInt("443");
var SshPort = parseInt("22");
var Tr69Port = parseInt("7547");
var SnmpPort = parseInt("161");
var SyslogPort = parseInt("514");
var CloudPort = parseInt("2023");
var DrpPort = parseInt("64999");
var RecordPort = parseInt("2999");
var RadiusPort = parseInt("1645");

/**��ĸ�����ֺͰ���ַ�(��`\��˫�������������ַ���)*/
function string_valid_check(str) 
{
    return str.match(/^[!\u0023-\u005B\u005D-\u005F\u0061-\u007E]+$/);
}

//ÿ���ֽ���0-127֮��
function passwd_valid_check(str) 
{
    return str.match(/^[\x00-\x7F]+$/);
}

function ipverify(ip_string){
	var c;
	var n = 0;
	var ch = ".0123456789";
	if (ip_string.length < 7 || ip_string.length > 15)
		return false;
	for (var i = 0; i < ip_string.length; i++){
		c = ip_string.charAt(i);
		if (ch.indexOf(c) == -1)
			return false;
		else{
			if (c == '.'){
				if(ip_string.charAt(i+1) != '.')
					n++;
				else
					return false;
			}		
		}
	}
	if (n != 3)
		return false;
	if (ip_string.indexOf('.') == 0 || ip_string.lastIndexOf('.') == (ip_string.length - 1))
		return false; 
		
	szarray = [0,0,0,0];
	var remain;
	var i;
	for(i = 0; i < 3; i++){
		var n = ip_string.indexOf('.');
		szarray[i] = ip_string.substring(0,n);
		remain = ip_string.substring(n+1);
		ip_string = remain;
	}
	szarray[3] = remain;
	for(i = 0; i < 4; i++){
		if (szarray[i] < 0 || szarray[i] > 255){
			return false;
		}
	}		
	return true;	
}

function convert2CompleteIpV6(ip)
{
    var ipV6=ip;
    var index=ip.indexOf("::");
    if(index>0)
	{
        var size=8-(ip.split(":").length-1);
        var tmp="";
        for(var i=0;i<size;i++)
		{
            tmp+=":0";
        }
        tmp+=":";
        ipV6=ip.replace("::",tmp);
    }
	else if(index==0)
	{
        ipV6=ip.replace("::","0:0:0:0:0:0:0:");
    }
    return ipV6;
}

function isIPv6Equals(src,des)
{
	var srcArr=convert2CompleteIpV6(src).split(":");
    var desArr=convert2CompleteIpV6(des).split(":");
	if(srcArr.length != desArr.length)
	{
		return false;
	}
	if(srcArr.length != 8)
	{
		if(src == des)
		{
			return true;
		}
		return false;
	}
    for(var i=0;i<8;i++)
	{
        if(parseInt(srcArr[i],16)!=parseInt(desArr[i],16))
		{
            return false;
        }
    }
    return true;
}

function is_ipv4_addr(ip_string)
{
	if(ip_string.length == 0)
    {
		return false;
	}
    
	if (!ipverify(ip_string))
    {
		return false;
	}	
    
	return true;
}

function is_ipv6_addr(ip_string) 
{
    /** �����ж��Ƿ����: */
    return /:/.test(ip_string)
           &&ip_string.match(/:/g).length<=7 
           &&/::/.test(ip_string) 
             ?/^([\da-f]{1,4}(:|::)){1,6}[\da-f]{1,4}$/i.test(ip_string) 
             :/^([\da-f]{1,4}:){7}[\da-f]{1,4}$/i.test(ip_string); 
} 

function is_ip_addr(ip_string) 
{
	if(ip_string.length == 0)
    {
        return false;
    }
    
    if (is_ipv4_addr(ip_string) || is_ipv6_addr(ip_string))
    {
        return true;
    }

    return false;
}

function local_port_occupied_check(port)
{
    var LanguageIndex = parseInt("2");
    loadProperties(LanguageIndex, "menu");
    
    if ((SipPort == port) || (TelnetPort == port) || (WebPort == port) 
        || (WebsPort == port) || (SshPort == port) || (Tr69Port == port) 
        || (SnmpPort == port) || (SyslogPort == port) || (CloudPort == port)
        || (DrpPort == port) || (RecordPort == port) || (RadiusPort == port))
    {
        alert($.i18n.prop("SeiviceAlreadyUsed"));        
        return true;
    }
    
    if ((RtpBasePort <= port) && (RtpMaxPort >= port))
    {
        alert($.i18n.prop("RtpAlreadyUsed"));        
        return true;
    }

    return false;
}

function isIP_endGTstart(endIP, startIP)
{
	var vEnd = endIP.split('.');
	var vSta = startIP.split('.');
	var nSta = (parseInt(vSta[0])<<24) + (parseInt(vSta[1])<<16) + (parseInt(vSta[2])<<8) + (parseInt(vSta[3])<<0);
	var nEnd = (parseInt(vEnd[0])<<24) + (parseInt(vEnd[1])<<16) + (parseInt(vEnd[2])<<8) + (parseInt(vEnd[3])<<0);	  
	if (nEnd  < nSta)
	{
		return false;
	}

	return true;
}

function isValidMacAddress(MacAddress)
{
    var c = '';
    var num = 0;
    var i = 0, j = 0;
    var zeros = 0;
    var cnt_ff=0;
    addrParts = MacAddress.split('-');
    if (addrParts.length != 6)
    {
        return false;
    }

    for (i = 0; i < 6; i++)
    {
        if (addrParts[i] == '')
        {
            return false;
        }
        for (j = 0; j < addrParts[i].length; j++)
        {
			c = addrParts[i].toLowerCase().charAt(j);
			if ((c >= '0' && c <= '9')
				|| (c >= 'a' && c <= 'f'))
				continue;
			else
				return false;
		}

		num = parseInt(addrParts[i], 16);
		if ((num == NaN) || (num < 0) || (num > 255))
			return false;
		if (num == 255)
			cnt_ff++;
		if (num == 0)
			zeros++;
	}
	if ((zeros == 6) || (cnt_ff == 6))
		return false;

	return true;
}

function is_maskaddr(mask_string){
	var i,j;	
	var substr = mask_string;
	var val, cnt = 0, num = 128, pos = 0;
	a = new Array(32);

	if(mask_string.length == 0){
		return false;
	}
	if (!ipverify(mask_string)){
		return false;
	}	
    /** ��������ʱ��ȫΪ255��������������Ч��*/
    if(mask_string == "255.255.255.255")
	{
		return false;
	}
	if(mask_string == "0.0.0.0")
	{
		return true;
	}
	for(i = 0; i < 4; i++)
	{
		pos = substr.indexOf('.',0);
		if(pos == -1)
		{
			val = parseInt(substr);
		}
		else
		{
			val = parseInt(substr.substring(0, pos+1));
			substr = substr.substring(pos + 1, substr.length + 1);
		}
		for (j = 0; j < 8; j++)
		{
			a[8*i + j] = (val&(num>>j))>>(7-j);
		}
	}

	for(j = 0; j < 31; j++)
	{
		if(a[j] != a[j+1])
		{
			cnt++;
		}
	}
	if(cnt > 1 || (a[30] == 0 && a[31] == 1))
	{
		return false;
	}
	return true;
}
function is_gatewayaddr(gateway_string){
	if(gateway_string.length == 0){
		return false;
	}
	if (!ipverify(gateway_string)){
		return false;
	}	
	return true;
}
function is_dnsaddr(dns_string){
	if(dns_string.length == 0){
		return false;
	}
	if (!ipverify(dns_string)){
		return false;
	}	
	return true;
}
function is_subnet(ip,mask,subip,submask){
	var i = 0,j = 0, pos = 0, cnt = 0;
	var str_ip_a = ip, str_mask_a = mask, str_ip_b = subip, str_mask_b = submask;
	
	ip_a = new Array(4);
	mask_a = new Array(4);
	ip_b = new Array(4);
	mask_b = new Array(4);
	
	for(i = 0; i < 4; i++)
	{
		pos = str_ip_a.indexOf('.',0);
		if(pos == -1)
		{
			ip_a[i] = parseInt(str_ip_a);
		}
		else
		{
			ip_a[i] = parseInt(str_ip_a.substring(0, pos+1));
			str_ip_a = str_ip_a.substring(pos + 1, str_ip_a.length + 1);
		}
	}
	for(i = 0; i < 4; i++)
	{
		pos = str_mask_a.indexOf('.',0);
		if(pos == -1)
		{
			mask_a[i] = parseInt(str_mask_a);
		}
		else
		{
			mask_a[i] = parseInt(str_mask_a.substring(0, pos+1));
			str_mask_a = str_mask_a.substring(pos + 1, str_mask_a.length + 1);
		}
	}
	for(i = 0; i < 4; i++)
	{
		pos = str_ip_b.indexOf('.',0);
		if(pos == -1)
		{
			ip_b[i] = parseInt(str_ip_b);
		}
		else
		{
			ip_b[i] = parseInt(str_ip_b.substring(0, pos+1));
			str_ip_b = str_ip_b.substring(pos + 1, str_ip_b.length + 1);
		}
	}
	for(i = 0; i < 4; i++)
	{
		pos = str_mask_b.indexOf('.',0);
		if(pos == -1)
		{
			mask_b[i] = parseInt(str_mask_b);
		}
		else
		{
			mask_b[i] = parseInt(str_mask_b.substring(0, pos+1));
			str_mask_b = str_mask_b.substring(pos + 1, str_mask_b.length + 1);
		}
	}
	for(i = 0; i < 4; i++)
	{
		if((ip_a[i]&mask_a[i]) == (ip_b[i]&mask_a[i])
			&& mask_a[i] <= mask_b[i])
		{
			cnt++;
		}
	}
	if(cnt != 4)
	{
		return false;
	}
	return true;
}

function gateway_check(ip, mask, gateway){
	var i = 0, pos = 0;
	var str_ip = ip, str_mask = mask, str_gateway = gateway;
	
	ip = new Array(4);
	mask = new Array(4);
	gateway = new Array(4);
	
	for(i = 0; i < 4; i++)
	{
		pos = str_ip.indexOf('.',0);
		if(pos == -1)
		{
			ip[i] = parseInt(str_ip);
		}
		else
		{
			ip[i] = parseInt(str_ip.substring(0, pos+1));
			str_ip = str_ip.substring(pos + 1, str_ip.length + 1);
		}
	}
    
	for(i = 0; i < 4; i++)
	{
		pos = str_mask.indexOf('.',0);
		if(pos == -1)
		{
			mask[i] = parseInt(str_mask);
		}
		else
		{
			mask[i] = parseInt(str_mask.substring(0, pos+1));
			str_mask = str_mask.substring(pos + 1, str_mask.length + 1);
		}
	}
    
	for(i = 0; i < 4; i++)
	{
		pos = str_gateway.indexOf('.',0);
		if(pos == -1)
		{
			gateway[i] = parseInt(str_gateway);
		}
		else
		{
			gateway[i] = parseInt(str_gateway.substring(0, pos+1));
			str_gateway = str_gateway.substring(pos + 1, str_gateway.length + 1);
		}
	}

	for(i = 0; i < 4; i++)
	{
		if ((ip[i] & mask[i]) != (mask[i] & gateway[i]))
		{
            return false;
		}
	}
    
	return true;
}

function macverify(mac_string){
	var c;
	var n = 0;
	var ch = "-0123456789ABCDEFabcdef";
	if (mac_string.length != 17)
			return false;
	for (var i = 0; i < mac_string.length; i++){
		c = mac_string.charAt(i);
		if (ch.indexOf(c) == -1)
			return false;
		else{
			if (c == '-')
				n++;		
		}
	}
	if (n != 5)
			return false;
	for(var i = 2; i < 17; i += 3){
		if (mac_string.charAt(i) != '-')
			return false;
	}
	return true;	
}
function is_macaddr(mac_string){
	if(mac_string.length == 0){
		return false;
	}
	if (!macverify(mac_string)){
		return false;
	}
	return true;	
}
function is_number(num_string,nMin,nMax){
	var c;
	var ch = "-0123456789";
	if(num_string.length == 0){
		return false;
	}
	for (var i = 0; i < num_string.length; i++){
		c = num_string.charAt(i);
		if (ch.indexOf(c) == -1)
			return false;
	}
	if(parseInt(num_string) < nMin || parseInt(num_string) > nMax)
		return false;
	return true;
}
function is_number_range_ok(num_string,nMin,nMax){
	var c;
	var num1;
	var num2;
	c = num_string.indexOf('-',0);

	if(c == 0)
	{
		return false;
	}
	if(c == -1)
	{
		return is_number(num_string,nMin,nMax);
	}
	else
	{
		num1 = num_string.substring(0,c);
		num2 = num_string.substring(c+1,num_string.length+1);
		if(is_number(num1,nMin,nMax) && is_number(num2,nMin,nMax)
			&& parseInt(num1) < parseInt(num2))
			return true;
		return false;
	}
}
function is_first_xin(num_string,minlength,maxlength)
{
	var c;
	var nums="0123456789*#";

	if(num_string.length < minlength || num_string.length > maxlength)
	{
		return false;
	}
	c = num_string.charAt(0);
	if (c == '*')
	{
		return false;
	}
	for (var i = 0; i < num_string.length; i++)
	{
		c = num_string.charAt(i);
		if (nums.indexOf(c) == -1)
		{
			return false;
		}
	}
	
	return true;
}
function is_number_string(num_string,minlength,maxlength){
	var c;
	var nums="0123456789"
	if(num_string.length < minlength || num_string.length > maxlength)
	{
		return false;
	}
	for (var i = 0; i < num_string.length; i++)
	{
		c = num_string.charAt(i);
		if (nums.indexOf(c) == -1)
		{
			return false;
		}
	}
	return true;
}
function charCompare(szname,en_limit,cn_limit){
	var c;
	var ch = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_.<>,[]{}?/+=|\\'\":;~!#$%()` & ";
	if(szname.length > en_limit)
		return false;
	for (var i = 0; i < szname.length; i++){
		c = szname.charAt(i);
		if (ch.indexOf(c) == -1){
			if(szname.length > cn_limit)
				return false;
		}
	}
	return true;
}
function is_string(name_string){
	var EN_LIMIT = 64;	
	var CN_LIMIT = 32;
	if(name_string.length == 0){
		return false;
	}
	if(!charCompare(name_string,EN_LIMIT,CN_LIMIT)){
		return false;
	}
	else
		return true;
}

function check_dtmf_cadence(DTMFCadence)
{
	var i;
	var array = new Array();
	var v1, v2;

	for (i = 0; i < DTMFCadence.length; i++)
	{
		if ((DTMFCadence.charAt(i) < '0' || DTMFCadence.charAt(i) > '9') && DTMFCadence.charAt(i) != ',')
		{
			return false;
		}
	}
	
	array = DTMFCadence.split(',');
	if (array.length != 2)
	{
		return false;
	}

	v1 = parseInt(array[0]);
	v2 = parseInt(array[1]);
	if ((v1 < 50 || v1 > 200) || (v2 < 50 || v2 > 200))
	{
		return false;
	}

	return true;
}

function check_call_process_tone_str(CallProcToneStr)
{
	var i;
	var array = new Array();
	var f1, a1, f2, a2;

	for (i=0; i<CallProcToneStr.length; i++)
	{
		if ((CallProcToneStr.charAt(i) < '0' || CallProcToneStr.charAt(i) > '9') && CallProcToneStr.charAt(i) != ',')
		{
			return false;
		}
	}
	
	array = CallProcToneStr.split(',');
	if (array.length != 6 && array.length != 8)
	{
		return false;
	}

	f1 = parseInt(array[0]);
	a1 = parseInt(array[1]);
	f2 = parseInt(array[2]);
	a2 = parseInt(array[3]);
	if ((f1 < 300 || f1 > 4000) || (a1 < 62 || a1 > 692))
	{
		return false;
	}
	
	if ((f2 < 300 || f2 > 4000) || (a2 < 62 || a2 > 692))
	{
		return false;
	}
	
	return true;
}

function check_busy_tone_str(CallProcToneStr)
{
	var i;
	var array = new Array();
	var value;

	for (i=0; i<CallProcToneStr.length; i++)
	{
		if ((CallProcToneStr.charAt(i) < '0' || CallProcToneStr.charAt(i) > '9') && CallProcToneStr.charAt(i) != ',')
		{
			return false;
		}
	}
	
	array = CallProcToneStr.split(',');
	if (array.length != 8)
	{
		return false;
	}

    for (i = 0; i < 8; i++)
    {
        value = parseInt(array[i]);
        //����Ƿ�����Чֵ
        if (0 != value && (value < 70 || value > 3000))
        {
            return false;
        }

        //���ҵ�һ��Ϊ0��timeֵ
        if (0 == value)
        {
            //��һ��Ϊ0��ֵ������offtime
            if (1 == i%2)
            {
                return false;
            }
            else
            {
                //����ı���ȫΪ0����Ч
                i++
                for (; i < 8; i++)
                {
                    value = parseInt(array[i]);
                    if (0 != value)
                    {
                        return false;
                    }
                }
                break;
            }
        }
    }

	return true;
}

function check_ringing_tone_str(RingCadenceStr)
{
	var i;
	var array = new Array();
	var value;

	for (i=0; i<RingCadenceStr.length; i++)
	{
		if ((RingCadenceStr.charAt(i) < '0' || RingCadenceStr.charAt(i) > '9') && RingCadenceStr.charAt(i) != ',')
		{
			return false;
		}
	}
	
	array = RingCadenceStr.split(',');
	if (array.length != 6)
	{
		return false;
	}

    for (i = 0; i < 6; i++)
    {
        value = parseInt(array[i]);
        //����Ƿ�����Чֵ
        if (0 != value && (value < 100 || value > 10000))
        {
            return false;
        }

        //���ҵ�һ��Ϊ0��timeֵ
        if (0 == value)
        {
            //��һ��Ϊ0��ֵ������offtime
            if (1 == i%2)
            {
                return false;
            }
            else
            {
                //����ı���ȫΪ0����Ч
                i++
                for (; i < 6; i++)
                {
                    value = parseInt(array[i]);
                    if (0 != value)
                    {
                        return false;
                    }
                }
                break;
            }
        }
    }

	return true;
}

function esc_transform(esc_string)
{
	while(esc_string.indexOf("&lt;") != -1)
	{
		esc_string = esc_string.replace("&lt;", "<");
	}
		
	while (esc_string.indexOf("&gt;") != -1)
	{
		esc_string = esc_string.replace("&gt;", ">");
	}
    
    return esc_string;
}

function createxmlHttpRequest()
{
    if (window.XMLHttpRequest)
    {
        xmlHttp=new XMLHttpRequest();
    }
    else
    {
        xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
    }
}

function doRequestUsingGet(url,para,fn)
{
	createxmlHttpRequest();
	url += "?" + para + "&timestamp=" + new Date().getTime();
	xmlHttp.open("GET",url,true);
	xmlHttp.onreadystatechange = fn;
	xmlHttp.send(null);
}

function doRequestUsingPost(url,para,fn)
{
	createxmlHttpRequest();
	xmlHttp.open("POST",url,true);
	xmlHttp.onreadystatechange = fn;
	xmlHttp.send(para);
}

function getElementPos(elementId)
{    
	var ua = navigator.userAgent.toLowerCase();
	var isOpera = (ua.indexOf('opera') != -1);
	var isIE = (ua.indexOf('msie') != -1 && !isOpera); // not opera spoof
	var el = document.getElementById(elementId);
	if (el.parentNode === null || el.style.display == 'none')
	{
		return false;
    }
	var parent = null;
	var pos = [];
	var box;
	if (el.getBoundingClientRect) //IE
	{
		box = el.getBoundingClientRect();
		var scrollTop = Math.max(document.documentElement.scrollTop, document.body.scrollTop);
		var scrollLeft = Math.max(document.documentElement.scrollLeft, document.body.scrollLeft);
		return { x: box.left + scrollLeft, y: box.top + scrollTop };
	}
	else if (document.getBoxObjectFor) // gecko
	{
		box = document.getBoxObjectFor(el);
		var borderLeft = (el.style.borderLeftWidth) ? parseInt(el.style.borderLeftWidth) : 0;
		var borderTop = (el.style.borderTopWidth) ? parseInt(el.style.borderTopWidth) : 0;
		pos = [box.x - borderLeft, box.y - borderTop];
	}
	else // safari & opera
	{
		pos = [el.offsetLeft, el.offsetTop];
		parent = el.offsetParent;
		if (parent != el)
		{
			while (parent)
			{
				pos[0] += parent.offsetLeft;
				pos[1] += parent.offsetTop;
				parent = parent.offsetParent;
			}
		}
		if (ua.indexOf('opera') != -1 || (ua.indexOf('safari') != -1 && el.style.position == 'absolute'))
		{
			pos[0] -= document.body.offsetLeft;
			pos[1] -= document.body.offsetTop;
		}
	}
	
	if (el.parentNode)
	{
		parent = el.parentNode;
	}
	else
	{
		parent = null;
	}
	while (parent && parent.tagName != 'BODY' && parent.tagName != 'HTML')
	{ // account for any scrolled ancestors
		pos[0] -= parent.scrollLeft;
		pos[1] -= parent.scrollTop;
		if (parent.parentNode)
		{
			parent = parent.parentNode;
		}
		else
		{
			parent = null;
		}
	}
	return {x: pos[0],y: pos[1]};
}

function DisableButton() 
{ 
	for(var f=0;f<document.forms.length;f++)
	{
		var form=document.forms[f];
		for(var i=0; i<form.length; i++)
		{ 
			if(form[i].type=='submit')
			{ 
            	if(form[i].disabled != 'true')
                {
					form[i].disabled='true';
                }
			} 
            else if(form[i].type=='button')
            {
            	if(form[i].name!='Cancel'
                	&& form[i].name!='cancel'
                    && form[i].id!='Cancel'
                    && form[i].id!='cancel')
				{
                    if(form[i].disabled != 'true')
                    {
                        form[i].disabled='true';
                    }
                }
            }
		}
	} 
}

function DisableAllPage() 
{ 
	for(var f=0;f<document.forms.length;f++)
	{
		var form=document.forms[f];
		for(var i=0; i<form.length; i++)
		{ 
			form[i].disabled='true';
		}
	} 
}

function BlankCheck(string)
{
	if (string.indexOf(' ') >= 0)
	{
		return false;
	}
	return true;
}

function LastStrIsDigital(string, count)
{
	var c;
	var LastCh;
	var Digital = "0123456789";
	
	if (string.length == 0)
	{
		return false;
	}
	if (string.length >= count)
	{
		LastCh = string.substr(string.length - count).toLowerCase();
	}
	else
	{
		LastCh = string;
	}

	for (var i = 0; i < LastCh.length; i++)
	{
		c = LastCh.charAt(i);
		if (Digital.indexOf(c) == -1)
		{
			return false;
		}
	}
	return true;
}

function StringRange(stringlen, minlength, maxlength)
{
	if (stringlen <= 0 || minlength > maxlength)
	{
		return false;
	}
	
	if(stringlen < minlength || stringlen > maxlength)
	{
		return false;
	}
	return true;
}

/*
 * xhr.js - XMLHttpRequest helper class
 * (c) 2008-2010 Jo-Philipp Wich
 */

XHR = function()
{
	this.reinit = function()
	{
		if (window.XMLHttpRequest) {
			this._xmlHttp = new XMLHttpRequest();
		}
		else if (window.ActiveXObject) {
			this._xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
		}
		else {
			alert("xhr.js: XMLHttpRequest is not supported by this browser!");
		}
	}

	this.busy = function() {
		if (!this._xmlHttp)
			return false;

		switch (this._xmlHttp.readyState)
		{
			case 1:
			case 2:
			case 3:
				return true;

			default:
				return false;
		}
	}

	this.abort = function() {
		if (this.busy())
			this._xmlHttp.abort();
	}

	this.get = function(url,data,callback)
	{
		this.reinit();

		var xhr  = this._xmlHttp;
		var code = this._encode(data);

		url = location.protocol + '//' + location.host + url;

		if (code)
			if (url.substr(url.length-1,1) == '&')
				url += code;
			else
				url += '?' + code;

		xhr.open('GET', url, true);

		xhr.onreadystatechange = function()
		{
			if (xhr.readyState == 4) {
				var json = null;
				if (xhr.getResponseHeader("Content-Type") == "application/json") {
					try {
						json = eval('(' + xhr.responseText + ')');
					}
					catch(e) {
						json = null;
					}
				}

				callback(xhr, json);
			}
		}

		xhr.send(null);
	}

	this.post = function(url,data,callback)
	{
		this.reinit();

		var xhr  = this._xmlHttp;
		var code = this._encode(data);

		xhr.onreadystatechange = function()
		{
			if (xhr.readyState == 4)
				callback(xhr);
		}

		xhr.open('POST', url, true);
		xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
		xhr.setRequestHeader('Content-length', code.length);
		xhr.setRequestHeader('Connection', 'close');
		xhr.send(code);
	}

	this.cancel = function()
	{
		this._xmlHttp.onreadystatechange = function(){};
		this._xmlHttp.abort();
	}

	this.send_form = function(form,callback,extra_values)
	{
		var code = '';

		for (var i = 0; i < form.elements.length; i++)
		{
			var e = form.elements[i];

			if (e.options)
			{
				code += (code ? '&' : '') +
					form.elements[i].name + '=' + encodeURIComponent(
						e.options[e.selectedIndex].value
					);
			}
			else if (e.length)
			{
				for (var j = 0; j < e.length; j++)
					if (e[j].name) {
						code += (code ? '&' : '') +
							e[j].name + '=' + encodeURIComponent(e[j].value);
					}
			}
			else
			{
				code += (code ? '&' : '') +
					e.name + '=' + encodeURIComponent(e.value);
			}
		}

		if (typeof extra_values == 'object')
			for (var key in extra_values)
				code += (code ? '&' : '') +
					key + '=' + encodeURIComponent(extra_values[key]);

		return(
			(form.method == 'get')
				? this.get(form.getAttribute('action'), code, callback)
				: this.post(form.getAttribute('action'), code, callback)
		);
	}

	this._encode = function(obj)
	{
		obj = obj ? obj : { };
		obj['_'] = Math.random();

		if (typeof obj == 'object')
		{
			var code = '';
			var self = this;

			for (var k in obj)
				code += (code ? '&' : '') +
					k + '=' + encodeURIComponent(obj[k]);

			return code;
		}

		return obj;
	}
}

XHR.get = function(url, data, callback)
{
	(new XHR()).get(url, data, callback);
}

XHR.poll = function(interval, url, data, callback)
{
	if (isNaN(interval) || interval < 1)
		interval = 5;

	if (!XHR._q)
	{
		XHR._t = 0;
		XHR._q = [ ];
		XHR._r = function() {
			for (var i = 0, e = XHR._q[0]; i < XHR._q.length; e = XHR._q[++i])
			{
				if (!(XHR._t % e.interval) && !e.xhr.busy())
					e.xhr.get(e.url, e.data, e.callback);
			}

			XHR._t++;
		};
	}

	XHR._q.push({
		interval: interval,
		callback: callback,
		url:      url,
		data:     data,
		xhr:      new XHR()
	});

	XHR.run();
}

XHR.halt = function()
{
	if (XHR._i)
	{
		/* show & set poll indicator */
		try {
			document.getElementById('xhr_poll_status').style.display = '';
			document.getElementById('xhr_poll_status_on').style.display = 'none';
			document.getElementById('xhr_poll_status_off').style.display = '';
		} catch(e) { }

		window.clearInterval(XHR._i);
		XHR._i = null;
	}
}

XHR.run = function()
{
	if (XHR._r && !XHR._i)
	{
		/* show & set poll indicator */
		try {
			document.getElementById('xhr_poll_status').style.display = '';
			document.getElementById('xhr_poll_status_on').style.display = '';
			document.getElementById('xhr_poll_status_off').style.display = 'none';
		} catch(e) { }

		/* kick first round manually to prevent one second lag when setting up
		 * the poll interval */
		XHR._r();
		XHR._i = window.setInterval(XHR._r, 1000);
	}
}

XHR.running = function()
{
	return !!(XHR._r && XHR._i);
}