Required library edition:
Required library file: dhtmlxgrid_drag.js

enable drag without removing (copy instead of move)

• mode - {true/false} enable/disable mode

   //enable mercy drag
   mygrid.enableMercyDrag(true);
   //disable mercy drag
   mygrid.enableMercyDrag(false);

See also: enableDragAndDrop, enableDragOrder