How To Answer the Phone Call And Record the voice as wav file

Question

Hi all,
i need to develop one application that when i got call ,if i click the answer button in my .net application,it should answer tha call and record the voice as
a wav file how to do it.please help me.i know i have to use TAPI.but i dont know how to use.what are the devices i have to use.
can any one answer plzzzzz