function getSad(strength) {
                      if(strength > 9)      return sad_10;
                      else if(strength > 8) return sad_09;
                      else if(strength > 7) return sad_08;
                      else if(strength > 6) return sad_07;
                      else if(strength > 5) return sad_06;
                      else if(strength > 4) return sad_05;
                      else if(strength > 3) return sad_04;
                      else if(strength > 2) return sad_03;
                      else if(strength > 1) return sad_02;
                      else                  return sad_01;
                  }