Partial Class admin
    Inherits System.Web.UI.MasterPage
    Public PageName As String = ""

    Private Sub form1_Load(sender As Object, e As EventArgs) Handles form1.Load
        PageName = IO.Path.GetFileName(Request.PhysicalPath)
        Session("Key") = ConfigurationManager.AppSettings("KEY").ToString
        If Not Page.IsPostBack Then
            If IsNothing(Session("userid")) Then
                Response.Redirect("admin_login.aspx")
            End If
        End If

    End Sub

End Class