char n[10]={0,1,3,7,15,31,63},i;
void main()
{
trisa=0;trisb=0b11000000;portb=0;porta=0;
loop:
while(portb.f6==0 && i<6)
                        {
                        i++;
                        porta=i;
                        portb=n[i];delay_ms(500);
                        }
while(portb.f7==0 && i>0)
                        {
                        i--;
                        porta=i;
                        portb=n[i];delay_ms(500);
                        }
goto loop;
} 

char n[10]={0,1,3,7,15,31,63},i;
void main()
{
trisa=0;trisb=0b11000000;portb=0;porta=0;
loop:
while(portb.f6==0 && i<6)
                        {
                        i++;
                        portb=n[i];
                        if(i==2)porta=0b10101;
                        else porta=0;
                        delay_ms(500);
                        }
while(portb.f7==0 && i>0)
                        {
                        i--;
                        portb=n[i];
                        if(i==2)porta=0b10101;
                        else porta=0;
                        delay_ms(500);
                        }
goto loop;
}