how to set EnableEventValidation = false from userControl DotNetNuke

I am using DotNetNuke : tying to open custom confirmation message on "btnOk_Clik" i am getting following error 
A critical error has occurred.Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.
any suggestions ??
how can i set EnableEventValidation = false; from userControl? 
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