var cur_lyr;	// holds id of currently visible layer
function loadLyr(lyr) {
	if (cur_lyr) {
		var curcss = get_lyr_css(cur_lyr);
		if (curcss && cur_lyr) curcss.visibility="hidden";
	}
/*	per non cambiare il lyr al secondo clic identico
 if (cur_lyr == lyr) 
      { if(cur_lyr=="lyr1") curcss.visibility = "visible";///dw_hidden();
	    if(cur_lyr != "lyr1") lyr='lyr1';
	    else return;
		}
*/		
  cur_lyr = lyr;
  var curcss = get_lyr_css(cur_lyr);
  if (curcss) {
		curcss.visibility = "visible";
		curcss.zIndex = 1000;	// some browsers need z-index set
	}
}

// get reference
function get_lyr_css(id) {
	var lyr, lyrcss;
	lyr = (document.getElementById)? document.getElementById(id): (document.all)? document.all[id]: (document.layers)? getLyrRef(id,document): null;
	if (lyr) lyrcss = (lyr.style)? lyr.style: lyr;
	return lyrcss;
}

// get reference to nested layer for ns4
// from old dhtmllib.js by Mike Hall of www.brainjar.com

function getLyrRef(lyr,doc) {
	if (document.layers) {
		var theLyr;
		for (var i=0; i<doc.layers.length; i++) {
	  	theLyr = doc.layers[i];
			if (theLyr.name == lyr) return theLyr;
			else if (theLyr.document.layers.length > 0) 
	    	if ((theLyr = getLyrRef(lyr,theLyr.document)) != null)
					return theLyr;
	     }
		return null;
       }
}