code: function moveTo_(x, y, prevent) {
      var roundedIntervalX_, roundedIntervalY_;
      left_ = Math.round(x);
      top_ = Math.round(y);
      if (opt_drag_.intervalX>1) {
        roundedIntervalX_ = Math.round(left_%opt_drag_.intervalX);
        left_ = (roundedIntervalX_<halfIntervalX_)?(left_-roundedIntervalX_):(left_+(opt_drag_.intervalX-roundedIntervalX_));
      }
      if (opt_drag_.intervalY>1) {
        roundedIntervalY_ = Math.round(top_%opt_drag_.intervalY);
        top_ = (roundedIntervalY_<halfIntervalY_)?(top_-roundedIntervalY_):(top_+(opt_drag_.intervalY-roundedIntervalY_));
      }
      if (opt_drag_.container&&opt_drag_.container.offsetWidth) {
        left_ = Math.max(0,Math.min(left_,opt_drag_.container.offsetWidth-src.offsetWidth));
        top_ = Math.max(0,Math.min(top_,opt_drag_.container.offsetHeight-src.offsetHeight));
      }
      if (typeof currentX_ === "number") {
        if (((left_-currentX_)>opt_drag_.toleranceX||(currentX_-(left_+src.offsetWidth))>opt_drag_.toleranceX)||((top_-currentY_)>opt_drag_.toleranceY||(currentY_-(top_+src.offsetHeight))>opt_drag_.toleranceY)) {
          left_ = originalX_;
          top_ = originalY_;
        }
      }
      if(!opt_drag_.restrictX&&!prevent) {
        src.style.left = left_ + "px";
      }
      if(!opt_drag_.restrictY&&!prevent) {
        src.style.top = top_ + "px";
      }
    }
docs: Moves the element {@link src} to the given
  location.
  @param {Number} x The left position to move to.
  @param {Number} y The top position to move to.
  @param {Boolean} prevent Prevent moving?
  @private