我想在导入数据前，判断”身份证号码”和”在保月份”是否同时一致，如果存在该记录就不导入，不知下面的代码问题出在哪里？请指教，谢谢！

Dim dlg As New OpenFileDialog 

dlg.Filter= "Excel文件|*.xls" 

If dlg.ShowDialog = DialogResult.Ok Then 

    Dim c As Integer = 0

    Dim Book As New XLS.Book(dlg.FileName)

    Dim Sheet As XLS.Sheet = Book.Sheets(0)

    Tables("参加企业保险明细表").StopRedraw()

     MessageBox.Show("请确保Excel中的字段顺序为:姓名,身份证号码,在保月份,是否结清,备注,结清类型")

    Dim nms() As String = {"姓名","身份证号码","在保月份","是否结清","备注","结清类型"}

    For n As Integer = 1 To Sheet.Rows.Count -1

        Dim dr As DataRow = e.DataTable.find("身份证号码=\'" & e.DataRow("身份证号码") & "\' and 在保月份 = #" & e.DataRow("在保月份")& "#")

        If dr Is Nothing Then

            c = c + 1

            Dim r As Row = Tables("参加企业保险明细表").AddNew()

            For m As Integer = 0 To nms.Length - 1

                r(nms(m)) = Sheet(n,m).Value

            Next

        End If

    Next

    Tables("参加企业保险明细表").ResumeRedraw()

    DataTables("参加企业保险明细表").Save

    MessageBox.Show("导入完成,共导入" & c & "条记录")

End If