This PHP login script example is a very simple login system which you can use as a base for your future projects. You should note that it needs to be secured before using on a live system. Some things to do before using it: md5 the password and compare against a md5 encrypted version of the submitted form password, set cookie which can be then checked at the admin.php page if login was successful.
[ad name=”In Post (LU)”]
If you don’t like request based logins, you may also use PHP’s HTTP authentication.