BADI or User-exit for ME21N

Hi all,

I am looking for User exit for ME21N.

The Issue is,

Whenever user will enter Delivery Date at line item,

The latest GR date in Delivery tab(In Item Details) should show the same date as delivery date

For Ex. if Delivery date for item 10 is 26.07.2014 then Latest GR date field in the Delivery tab should also be 26.07.2014

What is the BADI or User exit to be used.

Thanks

Neha