i have a problem. i built the code below but the readkey doesnt seem to be working, i get 3 problems- 2 of them are "error: illegal expression" and the other is "fatal: syntax error,;expected but identifier READKEY found"


please help

here is my code-


program Lesson6Task3;

var
sLen:Integer;
sSearch,D:String;
mString,sString:String;
intPos,intLen:String;
Choice:Char;

begin
Writeln('Please enter a string or sentence');
Readln(mString);
Writeln('please choose functon');
Writeln('V- View the string');
Writeln('F- find the length of the string');
Writeln('S- search the string');
Writeln('D- Delete part of the string');
Writeln('C- Clear the string');
Choice=:readkey;

If Choice:= 'V' Then
begin
Writeln(mString);
end;

If Choice:= 'F' Then
begin
sLen := Length(mString);
end;

If Choice:= 'S' Then
begin
sSearch := Pos (D)
end;

If Choice:= 'D' Then
begin
Readln(mString);
Writeln('What do you want to delete from the string');
readln(sString);
intpos :=Pos (sString, mString);
intLen :=Length:=(sString);
Delete(mString, intPos, intLen)
end;

If Choice:= 'C' Then
begin
Readln(' ', sLen);
Readln(' ', sSearch);
Readln(' ', mString);
Readln(' ', sString);
Readln(' ', intPos);
Readln(' ', intLen);
end;

Else
Writeln('Please choose one of the funtions');

end.

program Lesson6Task3;

var
sLen:Integer;
sSearch,D:String;
mString,sString:String;
intPos,intLen:String;
Choice:Char;

begin
Writeln('Please enter a string or sentence');
Readln(mString);
Writeln('please choose functon');
Writeln('V- View the string');
Writeln('F- find the length of the string');
Writeln('S- search the string');
Writeln('D- Delete part of the string');
Writeln('C- Clear the string');
Choice=:readkey; (*It should be := instead of =: Also, readkey unfound *)
If Choice := 'V' Then (*It should be Choice = 'V'*)
begin
Writeln(mString);
end;

If Choice:= 'F' Then
begin
sLen := Length(mString);
end;

If Choice:= 'S' Then
begin
sSearch := Pos (D)
end;

If Choice:= 'D' Then
begin
Readln(mString);
Writeln('What do you want to delete from the string');
readln(sString);
intpos :=Pos (sString, mString);
intLen :=Length:=(sString);
Delete(mString, intPos, intLen)
end;

If Choice:= 'C' Then
begin
Readln(' ', sLen);
Readln(' ', sSearch);
Readln(' ', mString);
Readln(' ', sString);
Readln(' ', intPos);
Readln(' ', intLen);
end;

Else
Writeln('Please choose one of the funtions');

end.

Doesn't hurt if you insert this as 2nd line either: uses crt;

it must be there bec readkey and keypressed are crt functions