docs: function (evt) {
                  var event = new ariaDomEvent(evt);
  
                  if (event.type === "touchmove") {
                      var elementPosition = ariaTouchEvent.getPositions(evt);
                      if (elementPosition.length === 1) {
                          event.clientX = elementPosition[0].x;
                          event.clientY = elementPosition[0].y;
                      }
                  }
  
                  if (this._dragStartPosition && !this._dragStarted) {
                      this._startDrag(this._dragStartPosition);
                  }
  
                  var element = this._activeDrag;
                  if (element) {
                      // IE mouseup check - mouseup happened when mouse was out of window
                      if (evt.type !== "touchmove" && !evt.button) {
                          var browser = ariaCoreBrowser;
                          if (browser.isIE8 || browser.isIE7) {
                              event.$dispose();
                              return this._onMouseUp(evt);
                          }
                      }
  
                      element.move(event);
                  }
                  event.$dispose();
              }