Help S&M lights on, NON start

Hope someone can help... took delivery today of an 03 td5 auto, been starting fine all day, get it home, giving it a clean, when locking the horn sounded (didnt think it had done this before), now when I try and start it, nothing happens, doesnt turn over, but the S & M (Sport & Manual) lights flash on the dash. Have I done something or pressed something?, or have I got a problem? hope someone can help

sorted the horn part, but still no go!!