Visual Studio Web Test is not a user interface (GUI) testing tool.
It uses WebTestRequest (HTTP) object to send request to the server.
So if you want to test Client side logic it's not the right tool. You can, however, use it to verify that content sent and received across the wire is correct.
Itís actually more like LoadRunner than QTP.
you ca use Visual studio test edition in various ways.
Test case Creation and management
Bug reporting and bug tracking (need TFS )
Web testing (this is http web request testing)
So this is very useful