function set_categs(type)
{
  var cat1 = document.getElementById('AD_CATEGORY1');
  var cat2 = document.getElementById('AD_CATEGORY2'); 

  if(type=='featured')
   {cat1.disabled = false; cat2.disabled = false;}
  if(type=='regular')
   {cat1.disabled = false; cat2.disabled = true;}
  if(type=='none')
   {cat1.disabled = true; cat2.disabled = true;}
}