“Unable to get value of the property 'split': object is null or undefined” error in IE-Collection of common programming errors

I am trying to use ASP.NET AJAX Toolkit’s MaskedEditExtender Control (with MaskedEditValidator) in my web application. The control works fine in Google Chrome but IE9 throws a “Unable to get value of the property ‘split’: object is null or undefined” error while loading the page that contains the MaskedEditExtender controls.
The Visual Studio debugger breaks into MaskedEdit.MaskedEditBehavior.debug.js at the following statements:

var partdt = arr[0];
var parttm = arr[1];
if (parttm.split(" ").length == 2) 
{
    parttm += " " + parttm.split(" ")[1];  // breaks here
}
partdt = this.ConvFmtDate(partdt,loadFirst);

I have also tried using the

as mentioned in this post but it did not work. I am also using JQuery 1.4.2 in my application. Any Ideas??

Originally posted 2013-11-10 00:10:37.