how can i fix lights that wont flash when locking doors?

i have a ford focus 1.6Lx 2005 and until recently, when the fob was pressed twice to lock the car the lights would flash twice to confirm it was locked.yesterday this stopped happening and,although the car is still locking ,the lights are no longer flashing,also from inside the car,when using the internal door lock it is not locking all the doors.any info would be appreciated.