void main(){
TRISA=0B00011111;
TRISB=0B00000000;
a:
if(PORTA.f0=1){PORTB.f0=0}
if(PORTA.f0=0){PORTB.f0=1}
goto a;
}

void main(){
TRISA.f0=1;// input
TRISB.f0=0;// output
portb.f0=0;
while(1)
      {
       if(PORTA.f0==0){
                       PORTB.f0=~PORTB.f0;
                        delay_ms(250);
                      }
      }

}

sbit led at RB0_bit;
sbit led_dir at TRISB0_bit;
sbit sw at RA0_bit;
sbit led at TRISA0_bit;
void main(){
sw=1;// input
led_dir=0;// output
led=0;//off led
while(1)
      {
       if(sw ==0){
                     led=~led;
                    delay_ms(250);
                }
      }

}

void main(){
TRISA.f0=1;// input
TRISB.f0=0;// output
portb.f0=0;
while(1)
      {
       if(PORTA.f0==0){
                       PORTB.f0=1;
                        delay_ms(250);
                      }
      }

}