If you don't have logged in already in the main site, going to the admin panel will redirect you to the login form.
Simply fill the required login/password field and hit the "login" button.
If you have successfully logged in you will be presented the admin panel like shown in the Admin page. If you fail because you mistyped your password or you're not an admin (or you hit the form login timeout) you will be presented again the login form.
To logoff simply click the logoff link located at the extreme right area of the admin panel.
