CAPTCHA is a simple test to determine if a user is a computer or a human. It is used to prevent spam abuse on the websites. The goal of this tutorial is to demonstrate how to make your own simple CAPTCHA protection using PHP and AJAX technologies.

If you are developing a password-protected web site, you have to make a decision about how to store user password information securely. This article will show you how to encrypt user passwords with the md5 algorithm and how to start using encrypted passwords if you already have a user database ready.

An overview of three common steps your PHP program may take and what to wtch out for. These include verifying the input is correct, manipulating the input, and how to access your data.

MySQL injection in PHP-based websites is a serious security problem. This article will tell you how to know if your site is vulnerable to this issue and correct this problem.

A bash functions library that aims to give to the bash programmer the ability to create simple web form pages in real-time with session management and MySQL wrappers, to build a "Xdialog-like" application, also complex.

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This tutorial will teach you how to deal with special characters like HTML tags, white space, line breaks and more from a user submitted form and database output.

This article explains how to take precautions and format user input for display on your web site, describing the dangers of unfiltered output and how to make it safe.