function rollTab(name,over)
{
  if(window.document.images) {
    
    if (over) window.document.images[name].src = "images/nav/" + name + "_over.gif";
	else window.document.images[name].src =  "images/nav/" + name + "_off.gif";
  }
}

function rollButton(name,over)
{
  if(window.document.images) {
    
    if (over) window.document.images[name].src = "images/buttons/" + name + "_over.gif";
	else window.document.images[name].src =  "images/buttons/" + name + "_off.gif";
  }
}