var openImg = new Image();
     openImg.src ="http://advanced.comms.agilent.com/n2x/images/Template/Drop_Arrow.gif";
     var closedImg = new Image();
     closedImg.src ="http://advanced.comms.agilent.com/n2x/images/Template/Drop_Arrow_down.gif";
     function showBranch(branch)
     { 
         var obj = document.getElementById(branch);
         var objBranch = document.getElementById(branch).style;
         if(objBranch.display=="block")
             objBranch.display="none";
         else
             objBranch.display="block";
         swapFolder("I"+branch);
     } 
     function swapFolder(img)
     { 
         objImg = document.getElementById(img);
         if(objImg.src.indexOf("Drop_Arrow.gif") > -1) 
             objImg.src = "http://advanced.comms.agilent.com/n2x/images/Template/Drop_Arrow_down.gif"; 
         else 
             objImg.src = "http://advanced.comms.agilent.com/n2x/images/Template/Drop_Arrow.gif";
     }