title: Insert some java script using HTMLDocumentClass
body: <p>i would like to insert custom javascript to the head of the page
  all i have is this HTMLDocumentClass object,</p>
  
  <p>does anyone know how to do that?</p>
  
  <p>are there any security restrictions???</p>
  
  <p>can i change ids of elemnts that came with the page??</p>