/*
Credit:  http://garyblue.port5.com/webdev/show-hide.html
*/
function change(which) {
if(document.getElementById(which).style.display == "block") { document.getElementById(which).style.display = "none"; }
	
else {
   document.getElementById('div1').style.display = 'none';
   document.getElementById('div2').style.display = 'none';
   document.getElementById('div3').style.display = 'none';
   document.getElementById(which).style.display = 'block';
   }
}