function showBranch(branch){
  var objBranch = document.getElementById(branch).style;
  if(objBranch.display!="none")
    objBranch.display="none";
  else
    objBranch.display="block";
}

function swapFolder(img, toggle_plus, toggle_minus){
  objImg = document.getElementById(img);
  if(objImg){
    indexPlus = objImg.src.indexOf(toggle_plus);
    if(indexPlus > -1){
      srcBase = objImg.src.substring(0,indexPlus);
      objImg.src = srcBase + toggle_minus;
    }
    else{
      indexMinus = objImg.src.indexOf(toggle_minus);
      srcBase = objImg.src.substring(0,indexMinus);
      objImg.src = srcBase + toggle_plus;
    }
  }
}