function toggleElementVisibility(id){
   if(typeof(id.toLowerCase) != 'undefined') var d = document.getElementById(id);
   else var d = id;
   
   var reVisible = /Visible/gi
   var reHidden = /Hidden/gi
   
   if(d.className.match(reHidden)) 
      d.className = d.className.replace(reHidden, 'Visible');
   else if (d.className.match(reVisible)) 
		d.className = d.className.replace(reVisible, 'Hidden');
   else {
	   //if it doesn't have either classname we are assuming it is visible and want to hide it
	   d.className = d.className + " Hidden";
   }
}