Hello everyone, I've ran into something that's been confusing me. Here's my code snippet:

if (parent.scrollTop < parent.scrollHeight)
		if(document.fireEvent){  //IE
		   	setTimeout("document.fireEvent('onmousemove')", 10);
		}else{   //FF
		   	var changeEvent = document.createEvent("MouseEvents")
		   	changeEvent.initEvent("mousemove", true, true);
		   	setTimeout("document.dispatchEvent(changeEvent)", 10);

What happens in Firefox is when the setTimeout fires, it tells me that changeEvent is undefined. To me, it seems to be defined. Has anyone run into this before and know how to work around it?
Thank you,