To find the conversations you had with someone, open your Messaging Inbox and select a chat session.
3.Select the Purge pick list and select an option.
4.Select OK.
Chatting with Messaging
When you exchange more than one message with a single contact, your messages are grouped into a chat session. The upper part of the Chat View displays all messages you’ve exchanged with this contact, and the lower part provides a text entry area. You can carry on multiple chats at the same time and easily switch between them, using the pick list at the top of
the screen.
1.Press Messaging 
.
2.Do one of the following:
•Start a new chat: Select a message and reply to it.
•Continue an existing chat: Select a message with the chat icon 
.
3.Enter your message.
4.Select Send.
