compatible for both http1.0 and http1.1

["J. Peng" <peng.kyo@xxxxxxxxx>]

I need to config squid for reverse-proxy for this destination:

1) if clients are http/1.0 compatible, squid send http/1.0 to
original-server and response to clients with http/1.0 content.
2) if clients are http/1.1 compatible, squid send http/1.1 to
original-server and response to clients with http/1.1 content.

Squid 2.7 can send/response either http/1.0 or http/1.1 to
original-server/clients, but not both.
Please help, thanks in advance.