required field validatior disables fileuplad asp.net
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I am writing asp.net project in C#. The page consists of textboxes, file upload with possibility to choose multiple files and this is done with jquery, and also required field validator and submit button. 
The problem is when I click the button when one or more textboxes are empty the validators get  error that field is empty, but the fileupload gets disabled.
So I want to create my own required field validator with javascript. 
Does someone know how to solve this problem?