If Nz(DCount("[ItemCategory]", _
"tblInventory", _
"[PersonID] = " & Me.PersonID & " And " & _
"[ItemCategory] = '" & Me.ItemCategory & "' And " & _
"[ItemStatus] = 'Out'"), 0) Then
MsgBox("Your customer isn't wearing any " & Me.ItemCategory)
Me.Cancel = True
End If