Field validation of a single button only
Assign ValidationGroup to each validator and also to the button that should trigger validation (but not the the other button). Something like:
<asp:RequiredFieldValidator ValidationGroup='valGroup1' ... /><asp:Button ValidationGroup='valGroup1' Text='I trigger validation' ... />
How about setting a ValidationGroup?
Also you can use 'causesvalidation' to the button. If it is false Button will not response to Validation in aspx page.
Example:<asp:Button runat="server" Text="Cancel" CausesValidation="false" />