Unable to add a field to a segment in an existing IDoc

Hi people,

I am trying to add a new field to an existing IDoc segment (Z1BP_INCINV_CREATE_HEADER ) using the transaction we31, But it is not successful. I get an error message ' the segment cannot be changed'. It is Not a standard IDoc. i am able to add fields to the other segments. Can anyone suggest?

Thanks in advance.

Shwetha

Edited by: shwethag on May 12, 2010 1:33 PM