function prepare_db_number($number)
{
  if ( is_numeric($number) )
  {
    return $number;
  }
  return 0;
}

function prepare_db_string( $string, $encode_html_entities = FALSE )
{
	// If magic quotes are enabled then strip the existing slashes from the string first
	if(get_magic_quotes_gpc())
		$result = stripslashes(trim($string));
	else
		$result = trim($string);

	// Encode HTML entities if required
	if ( $encode_html_entities === TRUE )
		$result = htmlentities($result);

	// Return MySQL safe string
	return mysql_real_escape_string($result);
}