Thanks for the reply.
After googling for a while I found out how push_array() works and it didn't seem to be possible to add associative key to the field pushed but instead I found this solution:
$array = array('animal'=>'dog', 'name'=>'Offenbach', 'owner'=>'Mr Smith');
$array = array_push_assoc($array, 'food', 'postmans leg');
function array_push_assoc($array, $key, $value){
$array[$key] = $value;
return $array;
}
Link: http://www.phpro.org/examples/Array-Push-Assoc.html
Eh.. Simple solution . Problem solved!