function hideLayer(whichLayer) {
	var menuGroup;
	if (document.getElementById) {
		// Standard method
		menuGroup = document.getElementById(whichLayer).style;
	} else if (document.all) {
		// For Old IE versions
		menuGroup = document.all[whichLayer].style;
	} else if (document.layers) {
		// For NN4
		menuGroup = document.layers[whichLayer].style;
	}
		menuGroup.display = menuGroup.display? "":"none";
}
function showLayer(whichLayer) {
	var menuGroup;
	if (document.getElementById) {
		// Standard method
		menuGroup = document.getElementById(whichLayer).style;
	} else if (document.all) {
		// For Old IE versions
		menuGroup = document.all[whichLayer].style;
	} else if (document.layers) {
		// For NN4
		menuGroup = document.layers[whichLayer].style;
	}
		menuGroup.display = menuGroup.display? "":"block";
}