Hi Savnik. Assuming you have your pushbutton on porta.0, you can toggle the variable "pushbutton" either 0 or 1 by making it a bit variable.

PUSHBUTTON VAR BIT

START:
IF PORTA.0 = 1 THEN START
IF PORTA.0 = 0 THEN LET PUSHBUTTON = PUSHBUTTON + 1
GOSUB WAITFORRELEASE
IF PUSHBUTTON = 0 THEN UHF
IF PUSHBUTTON = 1 THEN VHF
GOTO START

WAITFORRELEASE:
PAUSE 25
IF PORTA.0 = 0 THEN WAITFORRELEASE
RETURN