You need to put some alert statements into your script to ensure that (a) execution is reaching that part of the script and (b) the script is dealing with expected values.
For example:
alert(document.getElementById('listofids'));
var allArray = document.getElementById('listofids').value.split(",");
alert(allArray[0]);
and:
ProdRev = document.getElementById('Mfg_Spec_Prod_Approval_Rev'+allArray[i]);
alert(ProdRev);