Something very wrong here!
var s = "ABCDEFGHIJKLMNOPQRSTUVWYZ";
s.substring(0,1)=A
s.substring(1,2)=B
s.substring(2,3)=C
s.substring(3,4)=D
s.substring(4,5)=E
s.substring(5,6)=F
s.substring(6,7)=G
s.substring(7,8)=H
s.substring(8,9)=I
s.substring(9,10)=J
s.substring(10,11)=K
s.substring(11,12)=L
s.substring(12,13)=M
s.substring(13,14)=NOPQRSTUVWYZ
s.substring(14,15)=OPQRSTUVWYZ
s.substring(15,16)=PQRSTUVWYZ
s.substring(16,17)=QRSTUVWYZ
s.substring(17,18)=RSTUVWYZ
s.substring(18,19)=STUVWYZ
s.substring(19,20)=TUVWYZ
s.substring(20,21)=UVWYZ
s.substring(21,22)=VWYZ
s.substring(22,23)=WYZ
s.substring(23,24)=YZ
s.substring(24,25)=Z