2 digit counting

char d1 '0';                   //the tens place.
char d2 '0';                   //the ones place.

void loop (){
  d2 ++;                       //increase the ones place by one.
  if (d2 > '9'){               //if the ones place is greater than '9'...
    d1 ++;                     //increase the tens place by one...
    d2 = '0';                  //set the ones place to '0'.
  }
  if (d1 > '9'){               //if the tens place is greater than '9'...
    d1 = '0';                  //set the tens place to '0'...
    d2 = '0';                  //set the ones place to '0'.
  }
  disp (d1,false,d2,false);    //send the two digits to the display function.
  delay(1000);                 //wait a second.
}