function planBG (){
  var ar = $A(document.getElementsByTagName('table'));
  for(var i=0; i<ar.length; i++) {
    if(ar[i].getAttributeNode && ar[i].getAttributeNode('class') && ar[i].getAttributeNode('class').value=='planTable') {
      var trs = $A(ar[i].getElementsByTagName('tr'));
      for(var j=0; j<trs.length; j++) {
        Event.observe(trs[j], "mouseover", function(e) {
          var el = Event.element(e);
          while(el.nodeName.toLowerCase()!='tr' && el.parentNode) {
            el = el.parentNode;
          }
          el.style.backgroundColor='#fffdd6';
        });
        Event.observe(trs[j], "mouseout", function(e) {
          var el = Event.element(e);
          while(el.nodeName.toLowerCase()!='tr' && el.parentNode) {
            el = el.parentNode;
          }
          el.style.backgroundColor='';
        });
      }
    }
  }
}