function validateUserExistence()
{ 
	var url="http://media247.co.uk/bizasia/newsletter/ajx_chkmail.php"
	var requestParams
	var useremail = document.unsubscribe.useremail.value 
	var username = document.unsubscribe.username.value 
		requestParams = "useremail="+useremail+"&username="+username
	
	xmlHttp=GetXmlHttpObject(stateChanged)
	xmlHttp.open("POST", "http://media247.co.uk/bizasia/newsletter/ajx_chkmail.php", false)
	var content_type = 'application/x-www-form-urlencoded';
	xmlHttp.setRequestHeader('Content-Type', content_type);
	xmlHttp.send(requestParams)
	return invalidUser;
} 
 

function stateChanged() 
{ 
	if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
	{ 
		invalidUser=xmlHttp.responseText;
		//alert(invalidUser);
	
	}
} 

function GetXmlHttpObject(handler)
{ 
var objXmlHttp=null

if (navigator.userAgent.indexOf("Opera")>=0)
{
alert("This example doesn't work in Opera") 
return 
}
if (navigator.userAgent.indexOf("MSIE")>=0)
{ 
var strName="Msxml2.XMLHTTP"
if (navigator.appVersion.indexOf("MSIE 5.5")>=0)
{
strName="Microsoft.XMLHTTP"
} 
try
{ 
objXmlHttp=new ActiveXObject(strName)
objXmlHttp.onreadystatechange=handler 
return objXmlHttp
} 
catch(e)
{ 
alert("Error. Scripting for ActiveX might be disabled") 
return 
} 
} 
if (navigator.userAgent.indexOf("Mozilla")>=0)
{
objXmlHttp=new XMLHttpRequest()
objXmlHttp.onload=handler
objXmlHttp.onerror=handler 
return objXmlHttp
}
}

function trim(str)
{
    if(!str || typeof str != 'string')
        return "";
    return str.replace(/^[\s]+/,'').replace(/[\s]+$/,'').replace(/[\s]{2,}/,' ');
}

function isEmpty(fname)
	{
		invalid = " ";
	
		flag = 1;
		for(ttt=0;ttt<fname.value.length;ttt++)
		{
			if(fname.value.charAt(ttt)!=invalid)
			{
				//alert('sdf');
				break;
			}
		}
		if(ttt==fname.value.length) flag = 0;
		if(flag==0) return true;
		if((fname.value=="") ||(fname.value==invalid))
			return true;
		else
			return false;
	}
function echeck(str)
{
		var at="@";
		var dot=".";
		var lat=str.indexOf(at);
		var lstr=str.length;
		var ldot=str.indexOf(dot);

		if (str.indexOf(at)==-1)
		{
		   alert("Invalid Email Address");
		   return false;
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr)
		{
		   alert("Invalid Email Address");
		   return false;
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr)
		{
		    alert("Invalid Email Address");
		    return false;
		}

		if (str.indexOf(at,(lat+1))!=-1)
		{
		    alert("Invalid Email Address");
		    return false;
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot)
		 {
		    alert("Invalid Email Address");
		    return false;
		 }

		 if (str.indexOf(dot,(lat+2))==-1)
		 {
		    alert("Invalid Email Address");
		    return false;		 }

		 if (str.indexOf(" ")!=-1)
		 {
		    alert("Invalid Email Address");
		    return false;
		 }
 		 return true;
}

	function validate()
	{
		if(trim(document.unsubscribe.username.value)=='' || document.unsubscribe.username.value =='Name')
		{
			 alert('Enter your Name')
			 document.unsubscribe.username.focus()
			 return false
		}
		 if(trim(document.unsubscribe.useremail.value)=='')
		{
			 alert('Enter your email address')
			 document.unsubscribe.useremail.focus()
			 return false
		}
			 if (echeck(document.unsubscribe.useremail.value)==false)
					{

						document.unsubscribe.useremail.focus();
						return false;
					}
		x = validateUserExistence();
		
		if(x!='')
		{
		 alert(x)
		 document.unsubscribe.useremail.focus();
		 return false;
		}
		else
		{
			alert('Your have been successfully subscribed.Thank you')
			return true
		}

	}