Шифр цезаря (не работает)

Function Cesar_Crypt (s:string):string;
Const
 SizeA = 26;
 EngA = 'ABCDEFGHIKLMNOPQRSTVXYZ';
Var i, P :integer;
 Temp,Result:string;
Begin
Temp:='';
For i := 1 to length (s) do if pos (s[i], EngA)<>0 then temp:=temp+s[i];
S:=temp;
For i:=1 to length (s) do
 Begin
 P:=pos (UpCase (s[i]), EngA)+10;
 If P>SizeA then P:=P-SizeA;
 Result:=Result+EngA[P];
 End;
End;
 
 
 
function Cesar_DeCrypt(s:string):string;
const
  SizeA = 33;
  EngA =
var i, P :integer;
    temp:string;
begin
s:=AnsiLowerCase(s);
temp:='';
 
for i := 1 to length(s) do if pos(s[i],EngA)<>0 then temp:=temp+s[i];
s:=temp;
for i:=1 to length(s) do
  begin
  P:=pos(s[i],EngA)-10;
  if P<=0 then P:=P+SizeA;
  Result:=Result+EngA[P];
  end;
end;
 
begin
 
Cesar_Crypt:=result;;
end.

function Cesar_Crypt(s:string):string;
const
  SizeA = 26;
  EngA = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
var i, P :integer;
    temp,result:string;
begin
Result := '';
s:=LowerCase(s);
temp:='';
 
for i := 1 to length(s) do if pos(s[i],EngA)<>0 then temp:=temp+s[i];
s:=temp;
for i:=1 to length(s) do
  begin
  P:=pos(s[i],EngA)+3;
  if P>SizeA then P:=P-SizeA;
  Result:=Result+EngA[P];
  end;
end;
 
 
function Cesar_DeCrypt(s:string):string;
const
  SizeA = 26;
  EngA = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
var i, P :integer;
    temp.result:string;
begin
Result := '';
s:=LowerCase(s);
temp:='';
 
for i := 1 to length(s) do if pos(s[i],RusA)<>0 then temp:=temp+s[i];
s:=temp;
for i:=1 to length(s) do
  begin
  P:=pos(s[i],RusA)-3;
  if P<=0 then P:=P+SizeA;
  Result:=Result+RusA[P];
  end;
end;
 
var
 aStr : String;
begin
aStr := Cesar_Crypt ('abc' );
writeln ( aStr );
writeln (Cesar_DeCrypt(aStr));
end.

const
  n = 3;
 
function CaesarEncipher(toCode: string): string;
var i, T: integer;
begin
  for i := 1 to length(toCode) do begin
    T := (Ord(toCode[ i ]) + n);
    if T >= 90 then dec(T, 90);
    toCode[ i ] := Chr(T);
  end;
  CaesarEncipher := toCode;
end;
 
function CaesarDecipher(toDecode: string): string;
var i, T: integer;
begin
  for i := 1 to length(toDecode) do begin
    T := (Ord(toDecode[ i ]) - n);
    if T < 0 then Inc(T, 90);
    toDecode[ i ] := Chr(T);
  end;
  CaesarDecipher := toDecode;
end;
 
{ применение: }
var
  s: string;
 
begin
  s := CaesarEncipher('just a Caesar');
  writeln(s);
  writeln('s = ', Caesarwriteln('s = ', CaesarDecipher(s));
end.

const
  n = 10;
 
function CaesarEncipher(toCode: string): string;
var
  i, T: integer;
begin
  for i := 1 to length(toCode) do 
  begin
    T := (Ord(toCode[ i ]) + n);
    if T >= 256 then dec(T, 256);
    toCode[ i ] := Chr(T);
  end;
  CaesarEncipher := toCode;
end;
 
function CaesarDecipher(toDecode: string): string;
var
  i, T: integer;
begin
  for i := 1 to length(toDecode) do 
  begin
    T := (Ord(toDecode[ i ]) - n);
    if T < 0 then Inc(T, 256);
    toDecode[ i ] := Chr(T);
  end;
  CaesarDecipher := toDecode;
end;
 
{ применение: }
var
  s: string;
 
begin
  writeln('in str ->> ');
  readln(s);
  s := CaesarEncipher(s);
  writeln(s);
  writeln('s = ', CaesarDecipher(s));
  readln
end.