Sql Injections What are they, and how to prevent them?

[rsf 0]

always use addslashes() to usernames to prevent sql injections even if your code doesn't allow them, because you never know when you'll accidentally type error prone code and not realize it.Also don't allow users to use their scripts on your site. I don't know why you would do this, but this is something you should definately NOT do.<?include($_GET['url']);?>if you do something like that anyone can include their site into your url and run scripts that query your database for passwords, steal your scripts, whatever.