AJAX core code

This is the core code needed to create an AJAX object:

<script type="text/javascript">
function ajaxDataGet(){

var ajaxObject;  //the variable that will store the object
	
  try{
	
	// Opera 8.0+, Firefox, Safari, Netscape 7
		ajaxObject = new XMLHttpRequest();
  } 
  
  catch (e){ 
	
	// Internet Explorer
		
	try{
	
   	  ajaxObject = new ActiveXObject("Msxml2.XMLHTTP");
		
	} 
	
	catch (e) { 
			
	  //if the above ActiveXObject did not work		
			
	  try{
		
		ajaxObject = new ActiveXObject("Microsoft.XMLHTTP");
		
		} 
		
		catch (e){
				//if AJAX is not supported at all
				alert("Your browser does not support AJAX!!");
				return false;
			}
		}
	}
}
</script>

The above is the core code to create an AJAX object.

The logical progression it follows is as such:

Create a function to set up an AJAX object
Create a variable within that function to store the AJAX object
Use a try.....catch block to try to crate an AJAX object using XML HttpRequest()
If that does not work, create an AJAX object using new ActiveXObject("Msxml2.XMLHTTP")
If that does not work, create an AJAX object using new ActiveXObject("Microsoft.XMLHTTP")
If that does not work, issue a message informing the user that their browser does not support AJAX

NOTE: You do not have to use the same exact code to create AJAX objects. But whatever code you use, the logical progression should be the same.