I know I said I would try to avoid asking elementary questions but since my skill level is low it seems I can't avoid it

I checked my PHP & MySQL reference books but had no luck.
Steve provided the following code to enable multiple fields to be displayed in the jump menu
class tables_mdl_user {
function getTitle(&$record){
return $record->display('username');
}
function titleColumn(){
return 'CONCAT(firstname," ",lastname)';
} }
and it works perfectly. I thought I'd be greedy and try to display the record name as 'firstname' , 'lastname' as follows:
class tables_mdl_user {
function getTitle(&$record){
return $record->display 'CONCAT(firstname," ",lastname)';
}
function titleColumn(){
return 'CONCAT(firstname," ",lastname)';
} }
But had no luck.
Also, (not directly related but) I noticed that in my production site, with 3367 records in a table, the jump menu does not appear at all...?
Jason