int y=1,i=0;
int x;
void on(char x)
 {
  portb=1;
  vdelay_ms(x*500);
  for(i=1;I<4;I++){
                      portb=2*portb;
                      vdelay_ms(x*500);
                      if(portb>8)portb=1;
                      }

 }

void main() 
{cmcon=7;
trisa=0xff;trisb=0;portb=0;
while(1)
        {
        if(porta.f1==0){while(porta.f1==0){on(y);}y++;}
        if(porta.f0==0){while(porta.f0==0){on(y);}y--;}
        if(y<1)y=1;
        else if(y>10)y=10;
        on(y);
        }
}