code: function(e) {
          if (this.enableKeys) {
              var kc = Event.getCharCode(e),
                  t  = this.thumb,
                  h  = this.getXValue(),
                  v  = this.getYValue(),
                  changeValue = true;
  
              switch (kc) {
  
                  // left
                  case 0x25: h -= this.keyIncrement; break;
  
                  // up
                  case 0x26: v -= this.keyIncrement; break;
  
                  // right
                  case 0x27: h += this.keyIncrement; break;
  
                  // down
                  case 0x28: v += this.keyIncrement; break;
  
                  // home
                  case 0x24: h = t.leftConstraint;    
                             v = t.topConstraint;    
                             break;
  
                  // end
                  case 0x23: h = t.rightConstraint; 
                             v = t.bottomConstraint;    
                             break;
  
                  default:   changeValue = false;
              }
  
              if (changeValue) {
                  if (t._isRegion) {
                      this._setRegionValue(Slider.SOURCE_KEY_EVENT, h, v, true);
                  } else {
                      this._setValue(Slider.SOURCE_KEY_EVENT,
                          (t._isHoriz ? h : v), true);
                  }
                  Event.stopEvent(e);
              }
  
          }
      }
docs: Executed when a keydown event happens with the control focused.
  Updates the slider value and display when the keypress is an
  arrow key, home, or end as long as enableKeys is set to true.
  @param {Event} e the keydown event