Confirmation MessageBox on Form Submission

Hi All,
        I am using VS05 + c# .  in my application when click on SUBMIT button then userinformation is submitted in database. after this i want to prompt messagebox  which is having  YES and No option   the message is like this "Do You want to insert personal information ? "
          If user click "Yes"  from MessageBox then only some fuction execute other wise nothing will happen.   How to do this stuff?
Thanks in advance.
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