Skip / Inactivate Field

Hi,

How can I skip the checque no field if MasPay CrLedFld value is cash and activate if it is bank?

Thanks

Code:

[Field : MasPay CrLedFld]
    Type : String
    Use : Name Field
    Table : CashBank LedgersExtract
    Storage : RBCBLedgerName
    Show Table : Always
    Case : Title Case
    Width : 50
    Align : Left


[Field : MasPay ChequeNoFld]
    Use : Name Field
    Width : @@shortwidth
    Storage : CheNumUDf
    Inactive  :  ?? ;;;If $$IsLedOfGrp:$RBCBLedgerName:$$GroupCash Then Yes Else No
    Skip    :    ??

 

Thank you Sir