html check box update when unchecked

http://stackoverflow.com/questions/1809494/post-the-checkboxes-that-are-unchecked

<input id='testName' type='checkbox' value='Yes' name='testName'>
<input id='testNameHidden'  type='hidden' value='No' name='testName'>

Before submitting the form , disabled the hidden field based on the checked condition

if(document.getElementById("testName").checked){
  document.getElementById('testNameHidden').disabled = true;
}