How to properly sanitize user input for MySQL

 
The get_magic_quotes_gpc function returns TRUE if magic quotes are active. In that case,any slashes that have been added to a string have to be removed or the function mysql_real_eascape_string could end up double-escaping some characters, creating corrupted strings.

<?php
function mysql_fix_string($string)
{
    if (get_magic_quotes_gpc()) $string = stripslashes($string);
    return mysql_real_escape_string($string);
}
?>