I recently upgraded Internet Explorer from IE6 to IE7. I added the "debugger" command to my javascript and I tried to debug, but I kept receiving an error message that said "There is no source code available for the current location." I found a few articles talking about this and I found information that VS2005 was going to be patched with VS2005SP1. The short of it is: there is a Microsoft knowledgebase article 930873. I downloaded the hotfix and all is working. Alternatively, you can move the javascript into an external file and it will work that way as well.