var activelayer = 0;

function showLay(no) {	
   if (no != activelayer) {
   
	if (document.layers) {
	   eval('document.layers.Layer'+activelayer+'.visibility="hide"');
	   eval('document.layers.Layer'+no+'.visibility="show"');
	} // ende if	
	
	else if (document.all) {
	   eval('document.all.Layer'+activelayer+'.style.visibility="hidden"');
	   eval('document.all.Layer'+no+'.style.visibility="visible"');
	} // ende else if
	
	else if (document.getElementById) { // Netscape 6 , Opera
	   eval('document.getElementById("Layer'+activelayer+'").style.visibility = "hidden"');
	   eval('document.getElementById("Layer'+no+'").style.visibility = "visible"');
	} // ende else if	
		
	activelayer = no;
	} // ende if
} // ende showLay