package booker;

require Exporter;
our @ISA = ("Exporter");

sub
Get_Booking_Course_Event
{
    my $BookingID = shift;

    my $dbh = DBI->connect("DBI:mysql:database=foo", "bar", "baz") or die $DBI::errstr;
    my $sth;

    $sth = $dbh->prepare("SELECT * FROM booking WHERE BookingID = $BookingID") or die $dbh->errstr;
    $sth->execute();
    $ref_booking = $sth->fetchrow_hashref;

    $sth = $dbh->prepare("SELECT * FROM event WHERE EventID = $ref_booking->{'EventID'}") or die $dbh->errstr;
    $sth->execute();
    $ref_event = $sth->fetchrow_hashref;

    $sth = $dbh->prepare("SELECT * FROM course WHERE CourseID = $ref_booking->{'CourseID'}") or die $dbh->errstr;
    $sth->execute();
    $ref_course = $sth->fetchrow_hashref;
}

our @EXPORT = qw/Get_Booking_Course_Event/;

1;

##</code><code>##

    my $ref_booking;
    my $ref_event;
    my $ref_course;
    &Get_Booking_Course_Event($ref->{'BookingID'});
    # the arg in this sub cd be one of a number of 
    # things depending on where in the script we are
    do_stuff_with($ref_booking, $ref_course, $ref_event);

##</code><code>##

    &Get_Booking_Course_Event($ref->{'BookingID'});
    # the arg in this sub cd be one of a number of 
    # things depending on where in the script we are
    do_stuff_with($booker::ref_booking, $booker::ref_course, $booker::ref_event);