If you want to capture keystrokes (like F11) and perform actions based upon that information (like opening a form), this article has the explanation of how to do that and sample code to help you out:
http://support.microsoft.com/kb/320584[
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However, you have tagged your question as ASP.NET. This won't work in the browser. To do that, you would need to look into Javascript or jQuery. Here is a possible solution:
http://stackoverflow.com/questions/424407/handling-key-press-events-f1-f12-using-javascript-and-jquery-cross-browser[
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One of the things that the above Stack Overflow question points out is that listening to the function keys in the browser is a bad idea. They are reserved for browser tasks (for example, F11 is usually reserved for fullscreen mode in the browser). Also, different browsers will work differently in how they capture the keys (or don't capture the keys). It makes for a much more difficult capture and you need to be aware of that going in.
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