var chkuser = 0;
function GetXmlHttpObject(){  
	var xmlHttp;
	if (window.XMLHttpRequest){ 
    	xmlHttp = new XMLHttpRequest(); 
	}else  if (window.ActiveXObject) {
	    try{
			 	xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");      
		}catch(e){
			try{
				 xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
			}catch(e){
				 alert("Your browser does not support AJAX!");
			 	return false;
		 	}
		 }
	 }
	return xmlHttp;
} 

function userVerify(value,url,para,id){  
	var xmlHttp=GetXmlHttpObject();
	var url = url+"?"+para+"="+value;
	xmlHttp.onreadystatechange=function(){
		if(xmlHttp.readyState==4){
          document.getElementById(id).value = xmlHttp.responseText;
		}
	}
	
	xmlHttp.open('GET',url,true);
	xmlHttp.send(null);
 }