When I logout page, cookie file is deleted automatically.

[deneb]

Hello all?

When I restart the page or just logout the page, cookie file is
deleted automatically.
What's wrong with me??

here is my code.

' If I success in Login process, Save user ID in cookie.
If IsLoginSuccess Then
Response.Cookies("USER_ID").Value = Args.UserID
Response.Cookies("USER_ID").Expires = DateTime.Now.AddDays(7)
End If

After above code is executed, I could find cookie file in "Cookie"
folder.
The problem is although Exprie date is not exceeded, Cookie file is
deleted when I logout or restart the page.

I use LoginView Control to manage login process with ASP.NET 2.0.

Any help will be welcomed. Thank you.