How to use MySQL Found_Rows() in PHP?

I try to avoid doing Count() because of performance issue. (i.e. SELECT COUNT() FROM Users)

If I run the followings in phpMyAdmin, it is ok:

  SELECT SQL_CALC_FOUND_ROWS * FROM Users;
  SELECT FOUND_ROWS();

It will return # of rows. i.e. # of Users.

However, if I run in in PHP, I cannot do this:

  $query = 'SELECT SQL_CALC_FOUND_ROWS * FROM Users;
    SELECT FOUND_ROWS(); ';
  mysql_query($query);

It seems like PHP doesn't like to have two queries passing in. So, how can I do that?