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

function hidelayer(lay){
if (ie4) {document.all(lay).style.visibility = "hidden";}
if (ns4) {document.layers(lay).visibility = "hide";}
if (ns6) {document.getElementById(lay).style.display = "none";}
}

function showlayer(lay) {
if (ie4) {document.all(lay).style.visibility = "visible";}
if (ns4) {document.layers(lay).visibility = "show";}
if (ns6) {document.getElementById(lay).style.display = "block";}
}