conversion from string to type 'integer' is not valid>> เวลาเพิ่มข้อมุลข้อมูลอื่นขึ้นแต่ตรงรหัสที่เป็น pk ไม่ขึ้นอ่ะค่ะ

id = CType(dr("Personnel_id").ToString.Substring(2, 4), Integer)

If (txtEquipmentID.Text = "") Or (txtEquipmentName.Text = "") Or (txtDetail.Text = "") Or (cboSportType.Text = "") Or (txtEquipmentCost.Text = "") Or (txtEquipmentprice.Text = "") Or (cboSportType.Text = "") Then
            MessageBox.Show("กรุณาใส่ข้อมูลทั่วไปให้ครบ !!!", "ผลการตรวจสอบ", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            txtEquipmentID.Focus()
            Exit Sub
        End If

        If (txtNumDateLend.Text = "") Or (txtFineRate.Text = "") Or (txtCost.Text = "") Then
            MessageBox.Show("กรุณาใส่เงื่อนไขการยืมให้ครบ !!!", "ผลการตรวจสอบ", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            txtNumDateLend.Focus()
            Exit Sub
        End If

        If (txtEquipInStock.Text = "") Or (txtEquipInLend.Text = "") Or (txtEquipTotal.Text = "") Then
            MessageBox.Show("กรุณาใส่จำนวนอุปกรณ์ให้ครบ !!!", "ผลการตรวจสอบ", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            txtEquipInStock.Focus()
            Exit Sub
        End If

        If cboSportType.Text = "" Then
            MessageBox.Show("กรุณาระบุประเภทอุปกรณ์ !!!", "ผลการตรวจสอบ", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            cboSportType.Focus()
            Exit Sub
        End If

        If cboAgent.Text = "" Then
            MessageBox.Show("กรุณาระบุตัวแทนจำหน่าย !!!", "ผลการตรวจสอบ", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            cboSportType.Focus()
            Exit Sub
        End If

        Dim sqlEquipment As String = ""
        Try
            Select Case ActionFlag
                Case "Add"
                    sqlEquipment = "INSERT INTO Equipment (EquipmentID,SportsTypeID,Equip_name,Equip_Detail,AgentID,Cost,Equip_Price,"
                    sqlEquipment &= " NumberDateLend,FineRate,Equip_Cost,Equip_InStock,Equip_InLend,Equip_Total,"
                    sqlEquipment &= " Equip_InOrder,Equip_Status)"
                    sqlEquipment &= " VALUES ('" & txtEquipmentID.Text & "',"
                    sqlEquipment &= "'" & CStr(cboSportType.SelectedValue) & "',"
                    sqlEquipment &= "'" & txtEquipmentName.Text & "',"
                    sqlEquipment &= "'" & txtDetail.Text & "',"
                    sqlEquipment &= "'" & CStr(cboAgent.SelectedValue) & "',"
                    sqlEquipment &= CSng(txtEquipmentCost.Text) & ","
                    sqlEquipment &= CInt(txtEquipmentprice.Text) & ","
                    sqlEquipment &= CInt(txtNumDateLend.Text) & ","
                    sqlEquipment &= CInt(txtFineRate.Text) & ","
                    sqlEquipment &= CInt(txtCost.Text) & ","
                    sqlEquipment &= CInt(txtEquipInStock.Text) & ","
                    sqlEquipment &= CInt(txtEquipInLend.Text) & ","
                    sqlEquipment &= CInt(txtEquipTotal.Text) & ","
                    sqlEquipment &= CInt(lblEquipmentInOrder.Text) & ","

                    If chkEquipStatus.Checked = True Then
                        sqlEquipment &= "'0')"
                    Else
                        sqlEquipment &= "'1')"
                    End If

                Case "Edit"
                    sqlEquipment = "UPDATE Equipment "
                    sqlEquipment &= " SET EquipmentID='" & txtEquipmentID.Text & "',"
                    sqlEquipment &= " SportsTypeID='" & CStr(cboSportType.SelectedValue) & "',"
                    sqlEquipment &= " Equip_name='" & txtEquipmentName.Text & "',"
                    sqlEquipment &= " Equip_Detail='" & txtDetail.Text & "',"
                    sqlEquipment &= " AgentID='" & CStr(cboAgent.SelectedValue) & "',"
                    sqlEquipment &= " Cost='" & CSng(txtEquipmentCost.Text) & "',"
                    sqlEquipment &= " Equip_Price=" & CInt(txtEquipmentprice.Text) & ","
                    sqlEquipment &= " NumberDateLend=" & CInt(txtNumDateLend.Text) & ","
                    sqlEquipment &= " FineRate=" & CInt(txtFineRate.Text) & ","
                    sqlEquipment &= " Equip_Cost=" & CInt(txtCost.Text) & ","
                    sqlEquipment &= " Equip_InStock=" & CInt(txtEquipInStock.Text) & ","
                    sqlEquipment &= " Equip_InLend=" & CInt(txtEquipInLend.Text) & ","
                    sqlEquipment &= " Equip_Total=" & CInt(txtEquipTotal.Text) & ","
                    sqlEquipment &= " Equip_InOrder=" & CInt(lblEquipmentInOrder.Text) & ","


                    If chkEquipStatus.Checked = True Then
                        sqlEquipment &= " Equip_Status='0'"
                    Else
                        sqlEquipment &= " Equip_Status='1'"
                    End If

                    sqlEquipment &= " WHERE (EquipmentID='" & txtEquipmentID.Text & "')"
            End Select

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

            Dim tmpMSG As String = ""
            If ActionFlag = "Add" Then
                tmpMSG = "คุณต้องการเพิ่มข้อมูล ใช่หรือไม่ ?"
            ElseIf ActionFlag = "Edit" Then
                tmpMSG = "คุณต้องการแก้ไขข้อมูล ใช่หรือไม่ ?"
            End If

            Dim comEquipment As SqlCommand = New SqlCommand
            If MessageBox.Show(tmpMSG, "คำยืนยัน", MessageBoxButtons.YesNo, MessageBoxIcon.Question) = DialogResult.Yes Then
                With comEquipment
                    .CommandType = CommandType.Text
                    .CommandText = sqlEquipment
                    .Connection = Conn
                    .ExecuteNonQuery()
                End With
                MessageBox.Show("บันทึกลงฐานข้อมูล เรียบร้อยแล้ว !!!", "ผลการทำงาน", MessageBoxButtons.OK, MessageBoxIcon.Information)
            End If
        Catch ErrProcess As Exception
            MessageBox.Show("ไม่สามารถบันทึกรายการยืมอุปกรณ์ได้ เนื่องจาก " & ErrProcess.Message, "ข้อผิดพลาด", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            Exit Sub
            MessageBox.Show("คุณป้อนรหัสอุปกรณ์กีฬา ซ้ำ !!!", "ผลการตรวสอบ", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            txtEquipmentID.Focus()
            txtEquipmentID.SelectAll()
            Exit Sub
        End Try

        grbSearch.Enabled = True

        ControlStatus(False)

        btnAdd.Enabled = True
        btnEdit.Enabled = False

        btnSave.Visible = False
        btnCancel.Visible = False
        ClearData()
        txtEquipmentID.ReadOnly = False

        cmdMoveFirst.Enabled = False
        cmdMovePrevious.Enabled = False
        cmdMoveNext.Enabled = False
        cmdMoveLast.Enabled = False

        lblShowPositions.Text = ""
        txtSearch.Text = ""
        txtSearch.Focus()

 Private Sub AutoGenerateLendID()
        Dim sqlTmp As String = ""
        Dim comTmp As SqlCommand = New SqlCommand
        Dim drLend As SqlDataReader
        Dim tmpLendID As Integer = 0

        sqlTmp = "SELECT TOP 1 LendID FROM Lend ORDER BY LendID DESC"

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

        Try
            With comTmp
                .CommandType = CommandType.Text
                .CommandText = sqlTmp
                .Connection = Conn
                drLend = .ExecuteReader()


                drLend.Read()

                tmpLendID = CInt(CStr((drLend.Item("MemberID"))))
                tmpLendID = tmpLendID + 1
                LastLendID = tmpLendID.ToString("0000000")
            End With
        Catch
            LastLendID = "0000001"
        End Try

       drLend.Close()    
End Sub