access vba 求医, 这段有何问题

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Dim mysqln As String, mymax As Integer
    Set rsNum = New ADODB.Recordset
    Set rsNumm = New ADODB.Recordset
   
   
    mysqln = "select max(凭证号) as mymax from 清单 " _
        & "where month(日期)=" & Month(Now())
    rsNum.Open mysqln, CurrentProject.Connection, adOpenKeyset, adLockOptimistic
  
       Label81.Caption = "本月最大编号为" & rsNum!mymax

    Set rsNumm = New ADODB.Recordset
    mysqln = "select sum(借方金额) as a1,sum(贷方金额) as a2  from 清单 " & "where month(日期)=" & Month(Now())
    rsNumm.Open mysqln, CurrentProject.Connection, adOpenKeyset, adLockOptimistic
   
    If rsNumm!a1 <> rsNumm!a2 Then
       凭证编号.Value = rsNum!mymax
       Label82.Caption = "不平衡,建议编号为" & rsNum!mymax
      
   
   
     ElseIf rsNumm!a1 = rsNumm!a2 Then
   
       凭证编号.Value = rsNum!mymax + 1
       Label82.Caption = "平衡,建议编号为" & rsNum!mymax + 1
      
    End If
   
   rsNum.Close
   rsNumm.Close

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把  凭证号设为"数字"就好了!!!!   汗!!