สอบถามปัญหาการ วน loop for ครับ มันไม่ไป แต่ว่ากำหนด เริ่มต้นและสิ้นสุดแล้ว

Imports System.Data
Imports System.Data.SqlClient
Module Module1

    Public Const strConn As String = "Data Source=AoFza;Initial Catalog=DGE;Integrated Security=True"
    Public Conn As New SqlConnection(strConn)

    '***********************************
    Public tmpUserName As String = ""
    '**************  frmFixseat  *********************

    Public tmpsum As String = ""
    Public tmpArray As String = ""

    Public tmpRow As Integer
    Public tmpColumn As Integer
End Module

     With Conn
            If .State = ConnectionState.Open Then .Close()
            .ConnectionString = strConn
            .Open()
        End With

        Dim NumberToText As String = ""
        Dim sqlGraduate As String = ""
        sqlGraduate = "SELECT Graduate.*, Education.* FROM Graduate, Education "
        sqlGraduate &= " WHERE (Graduate.EdtID = Education.EdtID)"
        sqlGraduate &= " ORDER BY Graduate.GdtHonor,Education.EdtSort " ',Graduate.GdtFname

        Da = New SqlDataAdapter(sqlGraduate, Conn)
        Da.Fill(Ds, "Graduate")

        Dim num As Integer = Ds.Tables("Graduate").Rows.Count
        lblMaxGdt.Text = num

        Dim cmd As New SqlCommand(sqlGraduate, Conn)
        Dim dr As SqlDataReader = cmd.ExecuteReader

        With dr
            If .HasRows Then
                While .Read
                    Dim liv As New ListViewItem
                    liv.Text = CType(.Item("GdtID"), String)
                    liv.SubItems.Add(CType(.Item("EdtID"), String).ToString)
                    liv.SubItems.Add(CType(.Item("GdtRank"), String).ToString)
                    liv.SubItems.Add(CType(.Item("GdtTitle"), String).ToString)
                    liv.SubItems.Add(CType(.Item("GdtFname"), String).ToString)
                    liv.SubItems.Add(CType(.Item("GdtLname"), String).ToString)
                    liv.SubItems.Add(CType(.Item("GdtHonor"), String).ToString)
                    lsvGraduate.Items.Add(liv)
                End While
            End If
        End With
    End Sub
  Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click

        'MsgBox(tmpArray)

        Dim sqlAdd As String = ""
        Dim ComAdd As New SqlCommand

        Dim i As Integer = 0

        For tmpRow = 1 To txtRow.Text
            For i = 0 To lsvGraduate.Items.Count - 1
                For tmpColumn = 1 To txtColumn.Text
                    sqlAdd = "INSERT INTO Seat(SeatID,GdtID,RowName)"
                    sqlAdd &= "VALUES ('" & tmpRow & "',"
                    sqlAdd &= "'" & Val(lsvGraduate.Items(i).SubItems(0).Text) & "')"
                    sqlAdd &= "'" & tmpColumn & "')"
                    MsgBox(sqlAdd)
                Next
            Next
        Next

        'With ComAdd
        '.CommandType = CommandType.Text
        '.CommandText = sqlAdd
        '.Connection = Conn
        '.ExecuteNonQuery()

        MessageBox.Show("บันทึกที่นั่ง เรียบร้อยแล้ว !!!", "ผลการทำงาน", MessageBoxButtons.OK, MessageBoxIcon.Information)

        btnAdd.Enabled = True
        btnEdit.Enabled = True
        btnSave.Enabled = False
        btnCancle.Enabled = False
    End Sub