i have locked the passenger rear door on my ford fusion the child lick is on cant open door from inside or out side any help would be most appreciated thanks

Child locks only apply to the inside.  If you can't open it from outside, there's another fault.  Can you hear the central locking 'thud' on that door when you unlock the car?

yes i can

Ok that's a good sign.  Means the door module is getting power.  So it's likely to be the door latch that's faulty (unless the handle rod has come off).

You'll need to try and remove the inner plastic door panel for access to the latch which can then be manually opened.  It'll be tight with the door closed but hopefully it's manageable on the Fusion.  I've done it on other cars but not these unfortunately.