I have a script that changes the width of a div depending on the percentage and webpage page returns (A webpage on my site return the percentage of a file in a header and Ajax reads the header) Here is that script: http://pastebin.com/eGZFQvDK
This works great for Chrome. Internet explorer (at least in older IE) doesn't work at all. It doesn't say any errors but it doesn't change the width either... Firefox is pretty weird actually.... It changes the width properly but it also echos "Progress Bar Error: Ready State is 1" yet it is still changing the width properly. I could remove the error message but that's not really fixing the problem.
This seems to be a problem for lots of people but all the posts I read seem to be just for certain situations.
When you open the xhr and if request is asynch then you should use true instead. This should work for you.
xmlhttp.open("GET",'/progressbar.php?progress_key='+upload_id, true);