Updating Cellphone

Every time I received an text message or incoming calls,my cellphone is always saying that it has a low memory space.That is the message that come out also when ever I try to download songs or pictures.So,today I have decided to upgrade it.I looked for its manual and followed the instructions.My cellphone is working fast now,I am glad I did what I have to do.Bad thing about it is I have lost all my contact numbers but it is cool,I will just store them again,thank God I have the numbers stored from my other cellphone.