is there such a thing as source files for an asp.net site

Hi
I dont have much experience with asp.net
but i recently had to change the developers of my site being built in asp.net, to get the job  finalized.
My new developer says "where are the source files" and service layer files

Now my old programmer said there's no source files. this is asp.net, and that my new guy should open up the project as a "website", and that he used something called "typed datasets"



Now i know that programs get compiled, and there are source files, but are there source files my old dev is hiding?


If anyone can be of any help i would so appreciate it


Thanks



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