New's Software for HP Prime does not allow Cesar program to run

[tom234]

Hello,
I used cesar program in HP own sight paper
EXPORT CESAR() BEGIN
local n;
LOCAL S,M,K; ””M;
//The user is asked to enter the encrypted word
INPUT(n,”Insert in quotation marks”,”Encrypted word”); SIZE(n)S;
FOR K FROM 1 TO S DO
//This time we shift by 3 letters backwards M+CHAR(ASC(MID(n,K,1))-3)M;
END; PRINT(M); END;

It worked in last OS but in the new one I get error at ""M;

Can anyone tell me why it works in old OS and not in the new OS?