Hi Friend,
To define and enable a customized banner to be displayed before the username and password login prompts, use the banner login global configuration command.
When a user connects to the router, the message-of-the-day (MOTD) banner (if configured) appears first, followed by the login banner and prompts. After the user successfully logs in to the router, the EXEC banner or incoming banner will be displayed, depending on the type of connection.
Read this link for more details on banner login command
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/ffun_r/ffrprt1/frf004.htm#wp1017507
For banner motd
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/ffun_r/ffrprt1/frf004.htm#wp1017571
HTH, if yes please rate the post.
Ankur