src/jquery.nstSlider.js
function (nextLeftGripPositionPx, nextRightGripPositionPx) {
             var $this = this;

             var draggableAreaLengthPx = _methods.getSliderWidthPx.call($this) - $this.data('left_grip_width');

             //
             // Validate & Move
             //
             if (nextRightGripPositionPx <= draggableAreaLengthPx && 
                 nextLeftGripPositionPx >= 0 &&
                 nextLeftGripPositionPx <= draggableAreaLengthPx && 
                 (!$this.data('has_right_grip') || nextLeftGripPositionPx <= nextRightGripPositionPx) ) {

                 var prevMin = $this.data('cur_min'),                        
                     prevMax = $this.data('cur_max');       

                 // note: also stores new cur_min, cur_max
                 _methods.set_position_from_px.call($this, nextLeftGripPositionPx, nextRightGripPositionPx);

                 // set the style of the grips according to the highlighted range
                 _methods.refresh_grips_style.call($this);

                 _methods.notify_changed_implicit.call($this, 'drag_move', prevMin, prevMax);
             }

             return $this;
         }
function (nextLeftGripPositionPx, nextRightGripPositionPx) {
             var $this = this;

             var draggableAreaLengthPx = _methods.getSliderWidthPx.call($this) - $this.data('left_grip_width');

             //
             // Validate & Move
             //
             if (nextRightGripPositionPx <= draggableAreaLengthPx && 
                 nextLeftGripPositionPx >= 0 &&
                 nextLeftGripPositionPx <= draggableAreaLengthPx && 
                 (!$this.data('has_right_grip') || nextLeftGripPositionPx <= nextRightGripPositionPx) ) {

                 var prevMin = $this.data('cur_min'),                        
                     prevMax = $this.data('cur_max');       

                 // note: also stores new cur_min, cur_max
                 _methods.set_position_from_px.call($this, nextLeftGripPositionPx, nextRightGripPositionPx);

                 // set the style of the grips according to the highlighted range
                 _methods.refresh_grips_style.call($this);

                 _methods.notify_changed_implicit.call($this, 'drag_move', prevMin, prevMax);
             }

             return $this;
         }
/*
Move slider grips to the specified position. This method is
designed to run within the user interaction lifecycle. Only call
this method if the user has interacted with the sliders
actually...

First the desired positions are validated. If values are ok, the
move is performed, otherwise it's just ignored because weird
values have been passed.