I tried this:
=IIf(IsNull[txtRetdBySol], Dateadd("d",35,[GuidDateReceived]),
IIf([Guide Type ID]="DGMAm", Dateadd("d",35,[GuidDateReceived]),
IIf([Guide Type ID]="DMGM",Dateadd("d",14,[GuidDateReceived]),
IIf([Guide Type ID]="SAOLET", Dateadd("d",14,[GuidDateReceived])))))
and when i try to...