// JavaScript Document

/* 
    Don't rely on ids as global variables to 
    reference elements. Use doc.getElementById 
*/ 

var myLayerCurr;

function layer_select(id)
{
if(myLayerCurr)
myLayerCurr.style.visibility='hidden';
myLayerCurr = document.getElementById(id);
myLayerCurr.style.visibility='visible';
}