t.preventDefault();
      this.back();
    }
    if ( aEvent.keyCode == 39 // right arrow
      || aEvent.keyCode == 40 // down arrow
      || aEvent.keyCode == 34 // page down
    ) {
      aEvent.preventDefault();
      this.forward();
    }
    if (aEvent.keyCode == 35) { // end
      aEvent.preventDefault();
      this.goEnd();
    }
    if (aEvent.keyCode == 36) { // home
      aEvent.preventDefault();
      this.goStart();
    }
    if (aEvent.keyCode == 32) { // space
      aEvent.preventDefault();
 