Protected Sub Page_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRender
	If Not Page.IsPostBack Then
	    AttemptWindowsAuth()
	End If
End Sub

Private Sub AttemptWindowsAuth()
	If Not Request.Browser.IsBrowser("IE") Then
	    Response.Write("User is not using IE...Browser does not support windows auth.")
	    Return
	End If

	If Request.Browser.IsMobileDevice Then
		Response.Write("IsMobileDevice")
		Return
	End If
	
	If Len(Request.QueryString("failedlogin")) > 0 Then
		Response.Write("failedlogin")
		Return
	End If
	
	If Regex.IsMatch(Request.UserHostAddress, ConfigurationManager.AppSettings("LanIPMask")) Then
		'Response.Write("Match")
		Response.Redirect("WinLogin.aspx?" + Request.QueryString.ToString(), True)
	End If
	
	If Me.Request.UserHostAddress.Equals("127.0.0.1") Or Request.UserHostName.ToLower().Equals("localhost") Then
		'Response.Write("Local")
		Response.Redirect("WinLogin.aspx?" + Request.QueryString.ToString(), True)
	End If
End Sub