PHP Form Hijacking. How to prevent form hijacking in PHP?

Following things can be done for preventing your PHP Form from Hijacking

1. Make register_globals to off to prevent Form Injection with malicious data.

2. Make Error_reporting to E_ALL so that all variables will be initialized before using them.

3. Make practice of using htmlentities(), strip_tags(), utf8_decode() and addslashes() for filtering malicious data in php

4. Make practice of using mysql_escape_string() in mysql.

5. User Input Sanitization-Never trust web user submitted data. Follow good clieint side data validation practices with regular expressions before submitting data to the server.

6. Form Submission Key Validation: A singleton method can be used to generate a Session form key & validating form being submitted for the same value against hidden form key params.