How to create Row Number in AX 2012 Form's GridControll ??

Hi,

I want to create a form with grid control in it. and I need one field in that, which shows row number. like

Sr. No.           ID                Name

1                 DAT-0001       ABC

2                 DAT-0002       XYZ

3                 DAT-0003       PQR

So, My question is How can I create this "Sr. No." Field in Grid of Form ???

I there any property for doing that or need to do any Code for it.

Thanks

Sumit