we have a old ish, uPVC door (about 15-20 years i think) anyway last few days the handle had began to stick when pushed down to open door. anyway today it took quite a bit of force to get the handle back up to the normal horizontal postion. the locks seem to be ok (nothing fancy just 2 round blots/pins that slide in to "U" shaped holders on door frame). Is the mechanisim knackered? or can it be fixed till we have the money to get hold of a new door. any help or advise is welcome. thanks.