var xmlHttp
function GetXmlHttpObject()
{
	var xmlHttp=null;
	try
	{
		 // Firefox, Opera 8.0+, Safari
		 xmlHttp=new XMLHttpRequest();
 	}
	catch (e)
 	{
 		//Internet Explorer
 		try
  		{
  			xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
  		}
 		catch (e)
		{
  			xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
  		}
 	}
	return xmlHttp;
}

function checkMemebership(textBox)
{
	var email = textBox.value;
	
	var radioObj = document.choice.membershipLevel;
	var radioLength = radioObj.length;
	
	for(var i = 0; i < radioLength; i++) 
	{
		if(radioObj[i].checked) {
				var memeberLevel = radioObj[i].value;
		}
	}
	
	xmlHttp=GetXmlHttpObject()
	if (xmlHttp==null)
	{
		alert ("Browser does not support HTTP Request")
		return
	}
	
	xmlHttp.onreadystatechange=function(){ 
			if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
 			{
 				var response = xmlHttp.responseText;
 				
 				if(response != 0)
 				{ 
					alert(response);
					
					document.f1.submitButton.disabled = true;	
					document.f3.submitButton.disabled = true;
 				}
 				else
 				{
 					document.f1.submitButton.disabled = false;
 					document.f3.submitButton.disabled = false;
 				}
			}
	}
	xmlHttp.open("GET","/includes/ajax/check-membership.php?email="+email+"&memberLevel="+memeberLevel,true)
	xmlHttp.send(null)
}