How to show the recently added item in listview containing more than some 30 items without having to scroll down?

Question

I am creating a chat application. In which I have used listview to contain the conversion between client and server. the problem is when more and more messages are added the listview gets bigger and the recently received as usual gets added to the bottom but the view always shows first ten msgs. i want the listview to show the the item most recently added. Can anyone help me with this.