drag and drop

what is wrong this code onDrag doesnt fire.

Code:

        var dd = Ext.create('Ext.dd.DDProxy', field.getEl().dom.id, 'dropPanelGroup', {
            isTarget: false
        });


        Ext.apply(dd, me.dragoverride);

    dragoverride: function () {
        return {
            onDrag: function (x, y) {
                if (!this.el) {
                    this.el = Ext.get(this.getEl());
                }


                this.originalXY = this.el.getXY();
            }
      }
   }

drag and drop