multiple criteria but allow null values

[Happy YN]

Thanks thats brilliant . I had already resigned myself to using a checkbox which would go for a different sql but this is better. I don't think however that if statement will work. I need something that will exclude the records if that field contains "Like deleted*"but let them thru if they are null or anything else. Your isnull(str...) does not do justice to this
Thanks again for all the time and patience
Added Later:
Done it! I added
IIf([Forms]![frmBook]![chkincDeleted]=True,True,(([tblbook].[mmoinfo] Like "deleted *") Or (IsNull([tblbook].[mmoinfo]))))

Thanks also for your explanation re sql statement lengths