I'm looking for a way to automate some simple testing of a web application. "Clicking x causes y" sort of testing. I want to write tests that can be run in a variety of browsers. I was thinking writing an inject-able script (bookmarklet sort of thing) which invokes click events and tests that elements exists might be a good way to go.
Are there any inherent dangers to this approach or major issues? Are there better alternatives? I don't want to get too involved in creating this test (don't want to create a test server, or go through a lot of setup), I just want to automate some repetitive testing.