I want to hide my messages in Nokia 5800 because sometimes when my classmates need to borrow my phone which is Nokia 5800, they will look in my Messages and see some private text messages. I want an application that will hide them all so that next time they borrow my phone and try to look in my messages they will need to enter passwords before they can access it. Is there any application that can do like that?? Pls. help.. Thank you so much