function doBranch(branch, img)
{
 var objBranch = document.getElementById(branch).style;
 if(objBranch.display=="block") objBranch.display="none";
 else objBranch.display="block";
 objImg = document.getElementById(img);
 if(objImg.src.indexOf('images/arrow_closed.gif')>-1) objImg.src = openImg.src;
 else objImg.src = closedImg.src;
}

var openImg = new Image();		openImg.src = "images/arrow_opened.gif";
var closedImg = new Image();	closedImg.src = "images/arrow_closed.gif";