mc74 transaction matl code and plant are in grey mode

Dear All,

When doing recording ( SHDB) for the MC74 ,materila code and plant fields are in grey mode but in transaction that fields are in enable mode.

bcaz of the above problem i could not able to do the recording to develop a BDC programme.

PLease tell me the solution ASAP.

Thanx in advance

Regards

Srinivas