var treeopened = null;

function opentree(block) {
  var cls = '';
  if (document.getElementById) {
    var el = document.getElementById (block);
    var tmpel;
    if (el && el.className) {
	el.className = (el.className == 'navOpened') ? 'navClosed' : 'navOpened';
	tmpel = document.getElementById( block + "_content" );
	tmpel.className = tmpel.className;
    }
  }
  if (navigator.appName == 'Microsoft Internet Explorer' && document.documentElement && navigator.userAgent.indexOf ('Opera') == -1) parent.setScrollInIE();
  return false;
}