//--------------------------------
var isNN4  = document.layers ;
var isIE4  = document.all ;
var isNN6  = document.getElementById && ! document.all;
//------------------------------------------------------------------------
function getLayer(id){
	if (isNN4) return document.layers[id];
	if (isIE4) return document.all[id];
	if (isNN6) return document.getElementById(id);
	return null;
}