focus starter problem?

i recentlybought an 05 1.4cl focus, with front end damage. the car will not turn over off the key, but starts immediately when a live is sent direct to the starter. it came with only 1key, which has a bluey-purple chip in the top (but it is not a key with a fob for central locking etc) had an electrical tester to relevant wires but there is no live to the starter at all, is there an electrical cut out switch? or possibly the original key is needed? any advice / ideas appreciated, thanks