delete statement.

I want to delete rows of an internal table based on a where condition when it_vbrk-aubel is initial

below is the code.

DELETE TABLE it_vbrk WITH TABLE KEY aubel = ''.

but it is giving an error message.

error message -

The declaration for the key field "VBELN" is incomplete. However,

"VBELN" is is contained in the key of table "IT_VBRK". and must be

filled.

any advice,

Shejal.