// JavaScript Document


divs = ['d1','d2','d3'];

function hideDivs() {
        for (var i=0; i<divs.length; i++)
          document.getElementById(divs[i]).style.display = 'none';

}

function showDiv() {
  hideDivs(); //hide them all before we show the next one.
  var randomDiv = divs[Math.floor(Math.random()*divs.length)];
  var div = document.getElementById(randomDiv).style.display = 'block';

  //setTimeout(showDiv,5000); //set a delay before showing the next div

}

/* 
Global "swap" holder 
Use value, null, if no layer initially visible 
*/ 
var currlayerId = "d1"; 

function toglayerold(id) 
{ 
if(currlayerId) setdisplay(currlayerId, "none"); 
if(id)setdisplay(id, "block"); 
currlayerId = id; 
} 

function toglayer(id)  { 
        if (id) { 
                 hideDivs();
                 setdisplay(id, "block"); 
        }
} 

function setdisplay(id,value) 
{ 
var elm = document.getElementById(id); 
elm.style.display = value; 
}