If clients turn off ActiveX support on their browser, bad things can happen if you don’t program for it.

The following code:

var xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); 

would break.  There is now a native XMLHTTPRequest object, similar to what the non-IE browsers do.

var xmlHttp = new XMLHttpRequest();
No ActiveX object is needed.  Here is the code that needs to be added to check the support of the native XMLHTTPRequest object

if (window.XMLHttpRequest)
{
   var xmlHttp = new XMLHttpRequest();
}
else
{
    if (window.ActiveXObject)
    {
        var xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
}