<?php
        function anti_injection( $user, $pass ) {
                # We'll first get rid of any special characters using a simple regex statement.
                # After that, we'll get rid of any SQL command words using a string replacment.
                $banlist = array (
                        "insert", "select", "update", "delete", "distinct", "having", "truncate", "replace",
                        "handler", "like", " as ", "or ", "procedure", "limit", "order by", "group by", "asc", "desc"
                );
                // ---------------------------------------------
                if ( eregi ( "[a-zA-Z0-9]+", $user ) ) {
                        $user = trim ( str_replace ( $banlist, '', strtolower ( $user ) ) );
                } else {
                        $user = NULL;
                }
                // ---------------------------------------------
                # Now to make sure the given password is an alphanumerical string
                # devoid of any special characters. strtolower() is being used
                # because unfortunately, str_ireplace() only works with PHP5.
                if ( eregi ( "[a-zA-Z0-9]+", $pass ) ) {
                        $pass = trim ( str_replace ( $banlist, '', strtolower ( $pass ) ) );
                } else {
                        $pass = NULL;
                }
                // ---------------------------------------------
                # Now to make an array so we can dump these variables into the SQL query.
                # If either user or pass is NULL (because of inclusion of illegal characters),
                # the whole script will stop dead in its tracks.
                $array = array ( 'user' => $user, 'pass' => $pass );
                // ---------------------------------------------
                if ( in_array ( NULL, $array ) ) {
                        die ( 'Invalid use of login and/or password. Please use a normal method.' );
                } else {
                        return $array;
                }
        }
?>