How to set in javascipt qlikviews checkbox

I wanna know how do i write the code in javascript so that appers in a properties page in the Qlikview Server and the text tag or label is defined in the . Actually i have to set the checkbox marked (checked) in javascript.!!

<Text   [Label=""] [Type="text,checkbox,select,color"]  [Select=""] [SelectLabel=""] [Width=""]  [Expression=""]  />