function init() {
IE = (document.all)
NC = (document.layers)
Opera = (document.getElementById)
}

function hiddenLayer(descr) {
init();
if(IE) eval('document.all["'+descr+'"].style.visibility = "hidden"')
if(NC) eval('document.layers["'+descr+'"].visibility = "hidden"')
if(Opera) eval('document.getElementById("'+descr+'").style.visibility = "hidden"')
}

function showLayer(descr) {
init();
if(IE) eval('document.all["'+descr+'"].style.visibility = "visible"')
if(NC) eval('document.layers["'+descr+'"].visibility = "visible"')
if(Opera) eval('document.getElementById("'+descr+'").style.visibility = "visible"')
}