CSV list of event interested users

Hi, I'm an Elgg newbie and I'm trying to build a view of interested users in a table or something like CSV format, but I'm stuck. I'm dealing with the array in "$users" variable in "display_event_users_.php".

this one: $users = event_calendar_get_users_for_event($event_id,$limit,$offset,false);

I can print the array with "print_r":

echo "<pre>";
echo "</pre>";

But I want  to know if there is a way to echo just some user attributes like name, username and email. If there is a way please let me know (:

Thank you in advance..