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';
		  return true;
		}
function toggleLayer1()
		{
		  var elem1, elem2, vis1, vis2;
		  if( document.getElementById )
		  	{ // this is the way the standards work
		    elem1 = document.getElementById("Residential");
		    elem2 = document.getElementById("Commercial");
		    }
		  else if( document.all ) 
		  	{// this is the way old msie versions work
		      elem1 = document.all["Residential"];
		      elem2 = document.all["Commercial"];
		    }
		  else if( document.layers ) 
		  	{// this is the way nn4 works
		  		elem1 = document.layers["Residential"];
		  		elem2 = document.layers["Commercial"];
		  	}
		  vis1 = elem1.style;
		  vis2 = elem2.style;
		  
		  // if the style.display value is blank we try to figure it out here
		  vis1.display = (vis1.display==''||vis1.display=='block')?'none':'block';
		  vis2.display = (vis2.display==''||vis2.display=='block')?'none':'block';
		}