function back_init() {
  if ( _back_onload ) { _back_onload(); }
  var _gbb = new getobj ( 'goback' );
  if ( _gbb.obj ) {
    _gbb.obj.onclick = function() { history.back(); }
    _gbb.style.visibility = 'visible';
  }
}

if ( window.onload ) { var _back_onload = window.onload }
window.onload = back_init;