Delete function no longer working and Java script error on page all of the sudden

Delete function no longer working and Java script error on page all of the sudden

I have a function in my commission tracker application that is a delete detail function.  It worked for a few months and all of the sudden nothing happens when I push it. I am also noticing all of the sudden that I am getting a java error on page message at the bottom of my IE7 window.  Any ideas?  We use this app everyday so any help would be appreciated.