hey..
i'm using a samsung galaxy S i9000 phone running android 2.3.3 gingerbread.
not rooted not flashed. still in ori condition.

Normally the bottom part of the phone has a bar containing "Phone, Contacts, Messages and Applications"

But suddenly there's only one left which is "Application"
The other 3 disappeared. It's available under the application menu, but i have to click application to access them.

How do i re-add them back into the bottom menu bar?

I was searching around but couldn't seem to find it, hence, i'm posting here. Thanks in advance.