function get_random() {
	var ranNum= Math.floor(Math.random()*5);
	return ranNum;
	}
function getaTab() {
	var what=get_random();
	var tab=new Array(3)
	tab[0]="home1";
	tab[1]="home2";
	tab[2]="home3";   
	var tabshow = (tab[what]); 			
	showhide(tabshow);
	}
function showhide(what) {
	switch (what) {
	case "home1":
	document.getElementById('home10').style.display = "none";
	document.getElementById('home11').style.display = "block";
	document.getElementById('home20').style.display = "block";
	document.getElementById('home21').style.display = "none";
	document.getElementById('home30').style.display = "block";
	document.getElementById('home31').style.display = "none";
	break;
	case "home2":
	document.getElementById('home10').style.display = "block";
	document.getElementById('home11').style.display = "none";
	document.getElementById('home20').style.display = "none";
	document.getElementById('home21').style.display = "block";
	document.getElementById('home30').style.display = "block";
	document.getElementById('home31').style.display = "none";
	break;
	case "home3":
	document.getElementById('home10').style.display = "block";
	document.getElementById('home11').style.display = "none";
	document.getElementById('home20').style.display = "block";
	document.getElementById('home21').style.display = "none";
	document.getElementById('home30').style.display = "none";
	document.getElementById('home31').style.display = "block";
	break;
	default:
	document.getElementById('home10').style.display = "block";
	document.getElementById('home11').style.display = "none";
	document.getElementById('home20').style.display = "block";
	document.getElementById('home21').style.display = "none";
	document.getElementById('home30').style.display = "none";
	document.getElementById('home31').style.display = "block";
	break;
	}
}
		
function addLoadEvent(func) { 
  var oldonload = window.onload; 
  if (typeof window.onload != 'function') { 
	window.onload = func; 
  } else { 
	window.onload = function() { 
	  if (oldonload) { 
		oldonload(); 
	  } 
	  func(); 
	} 
  } 
} 

addLoadEvent(getaTab);