function toggleLayer( whichLayer ) { var elem, vis; if( document.getElementById ) // this is the way the standards work elem = document.getElementById( whichLayer ); else if( document.all ) // this is the way old msie versions work elem = document.all[whichLayer]; else if( document.layers ) // this is the way nn4 works elem = document.layers[whichLayer]; vis = elem.style; // if the style.display value is blank we try to figure it out here 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'; }