function hideshow( whichLayer ){  var elem, vis;  if( document.getElementById ) 
elem = document.getElementById( whichLayer );  else if( document.all )  
elem = document.all[whichLayer];  else if( document.layers ) 
elem = document.layers[whichLayer];  vis = elem.style; 
if(vis.display==''&&elem.offsetWidth!=undefined&&elem.offsetHeight!=undefined)    
vis.display = (elem.offsetWidth!=0&&elem.offsetHeight!=0)?'block':'none';  
vis.display = (vis.display==''||vis.display=='block')?'none':'block';}