var ie4 = (document.all) ? true : false;
var ie5 = (document.all) ? true : false;
var ie6 = (document.all) ? true : false;
var ns4 = (document.layers) ? true : false;
var ns6 = (document.getElementById && !document.all) ? true : false;

function showlayer(lay)
{
        if (ns4) {
                document.layers[lay].visibility = "show";
        }
        else if (ns6) {
                document.getElementById([lay]).style.display = "block";
        }
        else if (ie4|ie5|ie6) {
                document.getElementById([lay]).style.visibility = "visible";
                document.getElementById([lay]).style.display = "inline";
        }

}

function hidelayer(lay)
{
        if (ns4) {document.layers[lay].visibility = "hide";}
        else if (ns6) {document.getElementById([lay]).style.display = "none";}
        else if (ie4|ie5|ie6) {
                document.getElementById([lay]).style.visibility = "hidden";
                document.getElementById([lay]).style.display = "none";
        }
}