Does anyone know if it is possible to view the source code of a vb EXE?. i.e. reverse the EXE to vb source code & show me how it was coded?

I have a piece of software which was written by a previous employee & i need to be able view his source code.
All that i have is the EXE which is already bundled up & finished, I need to extract the validation section from his code as it will be the same in my new project. (Validation section was massive so that's why i cant do it from scratch)

We own the license for the software already so theres no issues with legalities.

Are there any programs out there which can be downloaded to do this?

cheers