function DBinit(){
  var e=document.getElementsByTagName('form');
  for (var i=0; i<e.length;i++) {
    e[i].originalsubmit = e[i].submit;
    e[i].submit = function () {
      this.originalsubmit();
      _disablebuttons();
    }
  }
}

function _disablebuttons() {
  var e=document.getElementsByTagName('button');
  for (var i=0; i<e.length;i++) {
    e[i].disabled = true;
  }
}

YAHOO.util.Event.addListener(window, "load", DBinit);