I have a login page made in asp (vbscript). The logout link is just a link to the the login page. My ideia is to go to the link + delete cokkies at same time. That way the user cant do return.

Is it a good ideia? How can it be done (delete cokkies).

You can't actually delete the cookie from ASP, what you do instead is clear the values that show a user is already logged in.

Thanks for the reply.

You mean go back and clear the 2 txtbox (user and pass)?

Response.Cookies(CookieName).Expires = Date() - 1

Is that what you needed?

In the cookie or session you probably store some values that indicate the user has logged on successfully, maybe the username and a boolean value.
When they logout you set the boolean to false. If you are using sessions to maintain state between pages you would use:

<%session.abandon%>

Which would clear the session values thus effectively "logging out" the user.

The details really depend on how you are maintaining state in the first place.