web form compare code

Question

I would like to know what a good open source (free) tool that I can use to compare C#.2010 web form code. Basically I want to compare code that is in a visual studio.net professional environment to the same some that is obtained from Jetbrains dotPeek decompiler tool.

I want to see  if the source code I have is the same as the decompiled code.

Does visual studio.net 2010 professional edition have a code compare feature in it?  (I am not using team server foundation.) If so, I do I access the code comparison feature in visual studio.net 2010 for web forms?