I have connected a push-switch to a PortA.5 on PIC16F876A.But it's not responding.Here is the code:

DOWN VAR PORTA.5

if DOWN=0 Then
IF SETBAND = 1 THEN
SETHEAT=SETHEAT-1

write 1,setheat
ELSE
SETCOOL=SETCOOL-1
WRITE 2,SETCOOL
ENDIF
endif