How do i get the value of a DataKeyName of an edited row on a GridView?

[Red_Wizard_Shot_The_Food]

When a row is edited I would like to get the value of one of the data keys. The datakey being the ID column that is not displayed on the table but is part of the SQL select statment. So i can get the actual tables ID column value relating the to GridView row baing changed... so I can write my own update stored procedure. -- modified at 10:28 Monday 29th January, 2007