function showHideFolder(folderName) {
  var maxFolders = document.getElementById('maxFolders').value;
  if(document.getElementById(folderName).style.display=='none') {
    document.getElementById(folderName).style.display = 'block';
    document.getElementById(folderName+'PlusMinus').innerHTML = '[-]';
  } else {
    document.getElementById(folderName).style.display = 'none';
    document.getElementById(folderName+'PlusMinus').innerHTML = '[+]';
  }
}