remote key fob problem?

My remote key does not unlock the doors but can lock them what might the problem be thanks Ray
Ray, May 2014

Changed my battery in my key fob for mitshibishi shogun 54 plate.pressed the fob my alarm went off opened door and it stopped.its flashing when i press fob but when i put my key in to start my alarm goes off take key out and it stops.key fob flashers but wont lock doors and alarm wont knock off

brandie, January 2015