function ajaxFunction(Param)
   {
	  var xmlHttp;
	  xmlHttp=GetXmlHttpObject();
	  if (xmlHttp==null)
	  {
	  alert ("Your browser does not support AJAX!");
	  return;
	  }
      
	  var loaderphp = "process.php";	  
    
	 
		xmlHttp.onreadystatechange=function()
		{
			var browser=navigator.appName;

			if(xmlHttp.readyState==4)
			{
				if (xmlHttp.status == 200) {
					
						// retrieve the response
						response = xmlHttp.responseText;
						if (response.indexOf('y') != -1) {
							document.getElementById("serialNumber").disabled = false;
							document.getElementById("serialNumber").style.backgroundColor = '#FFFFFF'
						} else {
							document.getElementById("serialNumber").disabled = true;
							document.getElementById("serialNumber").value = "";
							document.getElementById("serialNumber").style.backgroundColor = '#ccc';
							document.getElementById("serialNumber").className = document.getElementById("serialNumber").className.substring(0,document.getElementById("serialNumber").className.lastIndexOf(' '));
							document.getElementById("serialNumber").parentNode.removeChild(document.getElementById("serialNumber").hasError);
							document.getElementById("serialNumber").hasError = null;
							document.getElementById("serialNumber").onchange = null;
							
						}
					
				
					

				}
			}
			
		}
		
		xmlHttp.open("GET", loaderphp+"?ajax="+Param,true);	 
		xmlHttp.send(null);
	}
   
   
   function GetXmlHttpObject()
  {
	if (window.XMLHttpRequest)
	{
		// code for IE7+, Firefox, Chrome, Opera, Safari		
		return new XMLHttpRequest();
	}
	if (window.ActiveXObject)
	{
		// code for IE6, IE5
		return new ActiveXObject("Microsoft.XMLHTTP");
	}
	return null;
  }