function my_getbyid(id)
{
   itm = null;
   if (document.getElementById)
   {
      itm = document.getElementById(id);
   }
   else if (document.all)
   {
      itm = document.all[id];
   }
   else if (document.layers)
   {
      itm = document.layers[id];
   }
   
   return itm;
}
function pageTab(num)
{
  //alert(thistotlepage);
  for (jj=1;jj<=thistotlepage;jj++)
  {
	  my_getbyid("page_main"+jj).style.display = 'none';
	  my_getbyid("page_menu"+jj).className='';
  }
	  my_getbyid("page_main"+num).style.display = 'block';
	  my_getbyid("page_menu"+num).className='hover';
}