object oriented PHP returning "object ID" for var

hey i've got a fairly large website starting up and heres a dumbed down version to show what its doing:

index.php:

PHP:

....

$pagenum=1;
$page -> DisplayMessages($pagenum);

.........


object oriented page:

PHP:

.......
function DisplayMessages($pagenum);
{
echo $pagenum;
}
.........


when i do this i get an output of "object ID #1" is there a way i can get it to output 1 as an integer and not object id?