/*
var dom = document.getElementById ? true : false;
var nn4 = document.layers ? true : false;
var ie4 = document.all ? true : false;


if (ie4) {
	var layerRef = document.all[layerName].style;
} else if (nn4) {
	var layerRef = document[layerName];
} else if (dom) {
	var layerRef = document.getElementById(layerName).style;
}
*/

function getLayerRefShowHideLayer(layerName) {
	var layerRef = (document.getElementById) ? document.getElementById(layerName).style : (document.all) ? document.all[layerName].style : (document.layers) ? document[layerName] : 0;
	return layerRef;
}


function showLayer(layerName) {
	getLayerRefShowHideLayer(layerName).visibility = "visible";
}


function hideLayer(layerName) {
	getLayerRefShowHideLayer(layerName).visibility = "hidden";
}