Logout button calls validation conrols in asp.net, how to avoid calling validations on click of Log out button?

I design a web form having some text box control,dropdown list control, radio button control,recaptcha control, and one submit button with asp button control. And I added a Link button with asp Link button control in right hand side up corner as log out button. The problem is even i press logout button the error validation controls of that page is being called, but it should be called only on submit button. Please check out my snap shots. Please help me regarding this, Thank you so much.. See Right hand side up corner, there is is logout button See the submit button as "ADD HOD" After clicking logout button all the error validation controls are being called, where it should be called by only Submit button(ADD HOD)


Just add this attribute on button: