function show_door(cat,door){
	//alert(cat+' '+door+' to '+thumbnails[cat]['element']);
	if( thumbnails[cat]['element']===null ){
		//alert('assinging '+cat);
		thumbnails[cat]['element'] = document.getElementById(thumbnails[cat]['tagName']);
		if( typeof(thumbnails[cat]['element'])!='object' || thumbnails[cat]['element']===null ){
		  thumbnails[cat]['element'] = false;
		  //alert('assinging '+cat+' image error!');
		}else{
		  //alert('assinging '+cat+' image: '+thumbnails[cat]['element'].src);
		}
	}
	//alert(cat+' '+door+' to '+thumbnails[cat]['element']);
	if( thumbnails[cat]['element']!==false ){
	  //alert(cached_thumbnails[door].src);
	  if( cached_thumbnails[door]!=null ){
			thumbnails[cat]['element'].src = cached_thumbnails[door].src;
			//alert('changed '+thumbnails[cat]['element'].src);
		}else{
		  thumbnails[cat]['element'].src = thumbnails[cat]['default'].src;
		  //alert('defaulted '+cached_thumbnails['default'].src);
		}
	}//else alert('cat '+cat+' element not found');
}