Multiple Username and Password accounts

I have the following code to log onto a separate Admin area within my site:

<script runat="server">

Public Sub Login(ByVal s As Object, ByVal e As EventArgs)

If UserName.Text = "admin" And Password.Text = "kb10" Then
Session("Admin") = True
Response.Redirect("default.aspx")

Else

Session("Admin") = False
LtlLogin.Text = "<p>Sorry you have provided incorrect login details.</p>"

End If
End Sub

</script>

How can I have it so it has another two or three username and password accounts to log on?

Thanks in advance!