clear a web form even when validation has not been successful

I have a button called clear that should clear all text boxes on a form. If I click clear the text boxes are emptied of their contents but only if what you have entered into those boxes is valid (i.e. all required field validators are valid=true). I put a break point in the code that clears the form but this isn't hit if there are validation problems. 
How can I have a button that resets the form without insisting that the user puts valid data into all fields first?
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