<%@ Control %>
<script language="VB" runat="server">

Dim m_Secure As Boolean = False
Public WelcomeMessage As String = "Welcome"

Sub Login_Click(ByVal sender As Object, ByVal e As EventArgs)
    If UsernameValidator.IsValid And PasswordValidator.IsValid Then
        UnsecurePanel.Visible = False
        Message.Text = WelcomeMessage & ", " & UserName.Text
        SecurePanel.Visible = True
        m_Secure = True
        Dim evt As new EventArgs()
        OnLogin(evt)
    End If
End Sub

Sub Logout_Click(ByVal sender As Object, ByVal e As EventArgs)
    If UsernameValidator.IsValid And PasswordValidator.IsValid Then
            Logoff()
    End If
End Sub

Public ReadOnly Property Secure() As Boolean
        Get
            Return m_Secure
        End Get
End Property   

Public ReadOnly Property User() As String
        Get
            Return UserName.Text
        End Get
End Property
    
Public Sub Logoff()
    UnsecurePanel.Visible = True
    UserName.Text = ""
    Password.Text = ""
    SecurePanel.Visible = False
    m_Secure = False
    Dim evt As new EventArgs()
    OnLogout(evt)    
End Sub


' Delegate declaration
Public Delegate Sub LoginHandler(ByVal sender As Object, ByVal e As EventArgs)

' Event declaration
Public Event Login As LoginHandler

' Raise the event by invoking the delegate, 
' sending "me", the current instance  of the class.
Protected Sub OnLogin(ByVal e As EventArgs)
    RaiseEvent Login(me, e) 'Invokes the delegates. 
End Sub

' Delegate declaration
Public Delegate Sub LogoutHandler(ByVal sender As Object, ByVal e As EventArgs)

' Event declaration
Public Event Logout As LogoutHandler

' Raise the event by invoking the delegate, 
' sending "me", the current instance  of the class.
Protected Sub OnLogout(ByVal e As EventArgs)
    RaiseEvent Logout(me, e) 'Invokes the delegates. 
End Sub    
</script>
<asp:panel id="UnsecurePanel" runat="Server">
    <asp:label runat="server" font-size="9pt">Username: </asp:label><br><asp:textbox id="UserName" runat="server" /><br>
    <asp:requiredfieldvalidator id="UsernameValidator" runat="server"  controltovalidate="UserName" errormessage="Please enter a username" style="color: red; font-size: 8pt"  /><br>
    <asp:label runat="server" font-size="9pt">Password: </asp:label><br><asp:textbox id="Password" runat="server" textmode="Password" /><br>
    <asp:requiredfieldvalidator id="PasswordValidator" runat="server"  controltovalidate="Password" errormessage="Please enter a password" style="color: red; font-size: 8pt" /><br>
    <asp:button id="LoginButton" text="Login" runat="server" onclick="Login_Click"/>
</asp:panel>
<asp:panel id="SecurePanel" runat="Server" visible="false"> 
    <asp:label id="Message" runat="server"/><br>
    <asp:linkbutton id="LogoutButton" runat="server" onclick="Logout_Click" text="Logout" style="font-size: 8pt; color: blue;"/>
</asp:panel>