DataGridView

Question

Hallo,
In a DataGridView I would like to increase the value in one of my datafields if a new row is addd.
 
Index | Description       |  ItemCode |  etc. 
233    | First record       |  1234545  |  etc.                 
234    | Second record  |  1234568   | etc.
          | Third record      |                   | 
If I add one row to the DataGridView I would like to automatically give  the value of 235 to the Index variable of the third record in the new row. ( i.e previous Index value + 1)
Is this possible?
 
Kind Regards,
 
Baily