loggoff hyperlink on master page

I am trying to add a hyperlink on master page for logging off current user. and intend to add formauthentication.logoff event in the on click event of this hyperlink. Now the problem is
1. asp:hyperlink is not having a server side onclick event.
2. I am not able to add asp:linkbutton, because master page is not having a form tag.
Please suggest right solution. It look like a small problem, because adding a logoff link in the site is quite a common scenario.
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