Even better, now when they have 4+ items, they have to get parcelpackaging anyhow;-)
*pads self on the back
PHP Code:
$a = array(100,100,100);
//$a = array(200,100,100);
if (in_array(100,$a)){
$tTnt_cnt = array_sum($a);
$tItems_cnt = count($a);
print (($tTnt_cnt/$tItems_cnt) == 100 && $tItems_cnt<=3)?"envelope":"parcel";
}