AJAX Call from Javascript Not Working Properly

[buckibooster]

function getXMLHttp(){	var xmlHttp;	try	{		//Firefox, Opera 8.0+, Safari		xmlHttp = new XMLHttpRequest();	}	catch(e)	{		//Internet Explorer		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 populateEntries(menu, userName, entryRow){	var xmlHttp = getXMLHttp();	xmlHttp.onreadystatechange = function()	{		if ((xmlHttp.readyState == 4) && (xmlHttp.status == 200) && (xmlHttp.responseText == ""))		{			window.alert("There are no records to view!");		}		else if ((xmlHttp.readyState == 4) && (xmlHttp.status == 200))		{			var response = xmlHttp.responseText;//			window.alert("PHP Response = '"+response+"'");		}	}	xmlHttp.open("GET", "getUsers.php", true);	xmlHttp.send(null);//	ADDITIONAL UNRELATED CODE THAT PARSES THE “RESPONSE,” CREATING A MULTIDIMIENSIONAL ARRAY, WHICH POPULATES A SELECT INPUT FOLLOWS ....}

I am using an AJAX call from a javascript to populate a SELECT input. This script is not working as shown in the code excerpt below. However, when I insert an alert of any type at the location shown by the comment, it works as planned. What could be causing this? I've also tried, without success, inserting a delay function after the AJAX call to allow time for the response to be returned (even with the readystate and status tests shown). Any suggestions as to how I can get this to work as desired?

Edited March 8, 2015 by buckibooster

[davej]

I am using an AJAX call from a javascript to populate a SELECT input.

 

 

Where is that code?

[buckibooster]

Moderator:

 

That part of the code is working and unrelated to the AJAX call problem. I choose to protect that code with the "additional unrelated code that ..." statement at the end of my code snippet.

[Ingolme]

You have to deal with the response inside the onreadystatechange event handler. The variable response is local to that function and is not accessible from outside.

[davej]

If you see the response text appear in the alert then this code is working also, so I don't see how you can conclude that the other code is "unrelated."

[buckibooster]

Thanks Ingolme! That not only solved the problem I was having but another related problem that I didn't even know I had. Thanks again!