How to disable validations

Hello one and all, 
                               I have written my code for inserting data in to SQL and i have given validations for each field while i am designing the page.  I am having link button as Back on my page when i click on that it should redirect me to previous page. But when i am clicking on that validations are arising. can any one tell how to do this.
 
Thanks and regards,
M.Dorababu

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