Database Update Code Problem

There is one database, one .aspx file (ASP.net) and two HTML files.
Quite simple really, all this code does is check to see whether the username and password is correct through two textboxes on the page and then takes whatever is in the third box and places that in the database. If it succeeds, it then shows the second HTML page (update.htm) if not, it will show the first HTML page (sorry.htm).

Now the problem: The page loads, enter in all the correct information and it shows that it is a success. Check back in the database to see if it HAS done anything and nothing has been changed.
Enter in the wrong password, and it takes you to sorry.htm like it should.

I have a feeling that the two variables created in the code are not matching. Even though it still takes me to the next page that says it has been successfully updated.

If anyone could help me, that would be greatly appreciated.