How to copy the content of a cell in dhtmlx grid

I am using dhtml grid in one of hands on activity. But not able to copy the content of a cell of a row by cntrl+c. Not sure how to make that work

Regards,
Khushhal

Here is the working example of this functionality:
http://www.dhtmlx.com/docs/products/dhtmlxGrid/samples/02_clipboard/01_grid_selection.html