here is a little trick to debug the JavaScript inside Visual studio or express edition of VWD

get all included office updates  from Microsoft updates install them.

enable the script debugger for IE or others inside internet explorer go to IE > internet options > advance > browsing

open a website in Visual studio or express put the breakpoint in JavaScript code and run them after setting as default browser internet explorer.

when the breakpoint function called he automatically show you all about the code you breakpoint. you can also change them and find the result in browser. for advance debugging their are many option already known in visual studio work same as C# debugging like Advanced Window, Local  , watch you can use all these 3 window for JavaScript debugging.