var visibleVar="null";
 var isinit="false";
 function init(){
 if (navigator.appName == "Netscape") {
                layerStyleRef="layer.";
                layerRef="document.layers";
                styleSwitch="";
                visibleVar="show";
        }else{
                layerStyleRef="layer.style.";
                layerRef="document.all";
                styleSwitch=".style";
                visibleVar="visible";
        }
    }
    function showHideLayerSwitch(layerName)
{ var targetId, targetElement;  
 
{     
targetId = layerName;     
targetElement = document.all(targetId);     
if (targetElement.style.display == "none") 
{        
targetElement.style.display = "";     
} 
else 
{        
targetElement.style.display = "none";     
}  
}}