Dispatch: ;remember, you need to CALL this address for it to work properly. Otherwise your program will most likely crash.
add a  ;this is a table of 16-bit values, so multiply the index by 2.
ld a,(hl)    ;get the low byte of the function addr. you wish to call
push af
   inc hl
   ld a,(hl) ;get the high byte of the function addr. you wish to call
   ld H,a    ;store the high byte in H
pop af
ld L,a       ;store the low byte in L
jp (HL)      ;now you've jumped to the desired function. Its RET will return execution to the instruction just after "CALL Dispatch"