code: function(direction, options) {
      
          this.direction = direction;
          this.CLASS_NAME += this.direction;
          
          OpenLayers.Control.prototype.initialize.apply(this, [options]);
      }
docs: Constructor: OpenLayers.Control.Pan
  Control which handles the panning (in any of the cardinal directions)
  of the map by a set px distance.
  
  Parameters:
  direction - {String} The direction this button should pan.
  options - {Object} An optional object whose properties will be used
  to extend the control.