Dim a As String
        Dim b As Boolean
        Dim dr As SqlDataReader
        Dim ConnStr As String
        ConnStr = ConfigurationManager.ConnectionStrings("gate").ConnectionString()
        Dim conn As New SqlConnection(ConnStr)

        conn.Open()
        Dim command As New SqlCommand("select * from visitors_pass", conn)
        dr = command.ExecuteReader
        b = False

        a = Integer.Parse(TextBox1.Text)
        While dr.Read()
            If (a = dr(0)) Then
                default4.label2.text = dr(0)
                default4.label4.text = dr(1)
                b = True
                dr.Close()
                conn.Close()
                Response.Redirect("default4.aspx")

                Exit While
            End If
        End While
        MsgBox("enter the numeric value")
        TextBox1.Focus()
        b = True



        If (b = False) Then
            MsgBox("no data matching to this serial number is found")

        End If
        dr.Dispose()
        conn.Dispose()
        dr.Close()
        conn.Close()
        TextBox1.Text = ""

    End Sub