PPS -
Download details: Script Debugger for Windows NT 4.0 and Later

There is your IE solution. Sucks, but better than nothing, or the godawful internal debugger:
Error at linr 105. Good luck guessing what the line number refers to.
Error: object undefined. Oh, we are not going to bother telling you what object we are refering to. Look at line 105 to figure it out. Sponsored by BigBill.com