Did you try using internet explorer's F12 (works in IE8 and up without additional installation)? It is also able to set a breakpoint on specific lines of code. Another thing is that the Ribbon is constructed outside of the form i-frame so you might be attaching
to the wrong process.
What is most likely causing the error though is that you've added the script call to the Ribbon, but you've added the actual script inside your form. If you want to access the code from the Ribbon you will need to use something like window.document.frames[0].myJavascriptFunction
rather than just myJavascriptFunction. Using F12 will also allow you to see which webresources (javascript) have been loaded, if your script appears twice it's likely that it's loaded in the window and the form i-frame. If it appears once it might only reside
in the i-frame and it won't be in the Ribbon scope. In the case of the latter calling the function through the Ribbon will actually cause a jump that reports the error, and this code is indeed not available in Visual Studio.
I hope this helps
- Alex
