Re: help please
I see from your website that you're attempting to make one yourself.
You should NOT be using mysql_* - check out PDO or MySQLi
As lemon-tree said, you need to know quite a bit about security to build a good login script. Of the top ten results on google for "php login script", most of them aren't good at all. Using PDO would reduce the risk of SQL injections, but there are other things to consider, such as brute forcing passwords (which your script currently doesn't make any attempt to stop)
You should also be using <input type="password" /> for the password field - as it is, anyone looking over my shoulder can see my password.
Make sure you're using a decent encryption for the password. You probably shouldn't be using md5, as quite a lot of people have broken it.
~Callum