New Post: How to debug the Javascript code

I am new to this area and maybe I am asking you a stupid question, but could anyone tell me how to debug the Javascript code of the Mileage Stats?

I opened the application with IE10, and opened the debug tool with F12. Then I clicked the View Sources button. I see there jquery...js files and modernizr...js file, but no mstats....js files.
I would like to set a breakpoint in a js file and to watch how the javascript code works, but how can I do it?

Atsushi