function setvis(id, vis) {
  var block = document.getElementById(id);
  var icon = document.getElementById(id+"b");
  if (vis=="none") {
    block.style.display = 'none';
    icon.src="/images/expand.gif";
  } else {
    block.style.display = '';
    icon.src="/images/collapse.gif";
  }
}

function iterate(vis) {
  var block;
  var bn = 0;
  while ((block = document.getElementById("u"+bn)) != null) {
    setvis("u"+bn, vis);
    bn++;
  }
}

function showall(id) {
  iterate("");
}

function hideall(id) {
  iterate("none");
}

function toggle(id) {
  var block = document.getElementById(id);
  if (block.style.display == "none") {
    setvis(id, "");
  } else {
    setvis(id, "none");
  }
}