[HELP] array_push, array_pop in codeigniter

[eluser]Unknown[/eluser]
i have some problems in array,i want to add and remove value inside an array like this :

example :

$username = array ('boby','terry','lucas');


then i want to change array values like this :


$username = array('boby','terry','john','nino');


How can i do this???


Hlp me plz...