Download WatIN Testing Framework for .NET
Just searching for the tool using which i can write unit test. May be simple ones. After searching, the best tool i can found out is WatiN. You can get more information on watin from following link
Don’t forget to download the Internet Explorer Developer Toolbar. This will help tremendously in exploring the structure of a webpage so you can create your test automation more easily.
Also you can get some more information from
There is application called WatiN recorder++ which can be used to record and get the source code of the test function. More information is on the following link
You can go through their site for more information. But my suggestion is to use as to write unit tests for asp.net pages.