Javascript xmlhttprequest asynchoronous call requires alert

[Pallavi R]

In the code below I have to have the alert statement marked by the two *s. Else firefox returns an empty 'temp' even though the 'webtext' is read correctly. How can I remove this requirement?

function getdatalinks(diagnosis,min_age,max_age,gender)
	{	
		var temp="";
		var urii="given URL";
    	
    	if (window.XMLHttpRequest) 
    	{// code for IE7+, Firefox, Chrome, Opera, Safari
    	xmlhttp=new XMLHttpRequest();
		} 
		else 
		{// code for IE6, IE5
    		xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
		}
  		
  		xmlhttp.open("GET",urii,true);
		xmlhttp.send(null);
		
  		xmlhttp.onreadystatechange=function()
  		{//the request is in ready state but not complete
  			if(xmlhttp.readyState==4 && xmlhttp.status==200)
  			{//request is complete		
  				webtext=String(xmlhttp.responseText);
				alert(webtext);
				temp=webtext;
  			}
  		};
			alert(temp); //**
			return(temp);
		
	}

[gits]

that is the purpose of a async call. you simply cannot return the value at that point where you do it ... the response is only reliably available in the onreadystatecha nge-callback. so the flow of your code has to consider that and just can proceed from there. call the next function that you need from inside the callback and you are fine.