ns4 = (document.layers)? true:false 
ie4 = (document.all)? true:false
ie5 =(document.getElementById)? true:false
ns6 = (document.getElementById && !document.all)?true:false;

function ShowHide(id){
var styleObj = (ns4)? document.layers[id] : (ie4)? document.all[id].style : document.getElementById(id).style;
if(styleObj.display == "none"){
styleObj.display = ""
}else{
styleObj.display = "none"
    }
    
}