How's that again? Can't quite parse the abstract form of your question. Perhaps you could restate with actual values instead of "A" and "B".
Tx for reply
I have Field called ASLM Certification and MEMBER type Field, Both Fields are in same table.
What want to do is If some value on "ASLM certification" field we shoud not be able to add "Member type" and If Some value on "Member Type" We shoud not able to add any values to "ASLM Certification"
On ASLM Certification add this validation rule:
IsEmpty ( MemberType )
Do the reverse for ASLM Certification and the user will be limited to entering data in one but not both of these fields.
You can also use scripts with OnObjectEnter triggers to deny entry to one of these two fields if the other is not empty. That approach prevents the error in the first place rather than catching it after the fact.
Thanks Phil :):)