function cleanInput($input) {
 
  $search = array(
    '@]*?>.*?@si',   // Strip out javascript
    '@<[/!]*?[^<>]*?>@si',            // Strip out HTML tags
    '@]*?>.*?@siU',    // Strip style tags properly
    '@@'         // Strip multi-line comments
  );
 
    $output = preg_replace($search, '', $input);
    return $output;
  }

function sanitize($input) {
    if (is_array($input)) {
        foreach($input as $var=>$val) {
            $output[$var] = sanitize($val);
        }
    }
    else {
        if (get_magic_quotes_gpc()) {
            $input = stripslashes($input);
        }
        $input  = cleanInput($input);
        $output = mysql_real_escape_string($input);
    }
    return $output;
}

// Usage:
$bad_string = "Hi!  It's a good day!";
  $good_string = sanitize($bad_string);
  // $good_string returns "Hi! It's a good day!"

  // Also use for getting POST/GET variables
  $_POST = sanitize($_POST);
  $_GET  = sanitize($_GET);