If Len(strFullFileName) = 0 Then
MsgBox "Missing filename.", vbCritical + vbOKOnly, "Error"
Exit Function
End If

If Len(strWorkbookName) = 0 Then
MsgBox "Missing sheet name.", vbCritical + vbOKOnly, "Error"
Exit Function
End If

If Len(strQueryName) = 0 Then
MsgBox "Missing query name or SQL string.", vbCritical + vbOKOnly, "Error"
Exit Function
End If