READLN not reading

I have a simple menu program that loops and ask the user to type a command,

but after the first command is typed the readln
doesn't read it properly

That doesn't affect much, but it is driving me mad.

has anybode had the same problem?

I am using freepascal BTW.

Thanks (the code is below)



PROGRAM LexDemo;

USES Scanner,Parser;



{VAR}

{ PRE   TRUE }
{ POST  Menu printed out }
PROCEDURE Menu();

BEGIN
  WRITELN('  Logical calculator      by Lucas S Silvs ');
  WRITELN('+------------------------------------------+');
  WRITELN('+           Main Menu                      +');
  WRITELN('+------------------------------------------+');
  WRITELN('| D -=> Display menu                       |');
  WRITELN('| L -=> Lex keyboard input                 |');
  WRITELN('| P -=> Parser the tokens into parse tree  |');
  WRITELN('| E -=> Ealuate the parser tree            |');
  WRITELN('| B -=> Bind an identifier to a value      |');
  WRITELN('| S -=> Show the values of all identifiers |');
  WRITELN('| Q -=> Quit                               |');
  WRITELN('| Print (m)enu                             |');
  WRITELN('| (l)ex token from standard input          |');
  WRITELN('| lex token(s) from standard input         |');
  WRITELN('| (r)ead string                            |');
  WRITELN('| lex tokens from s(t)ring                 |');
  WRITELN('+------------------------------------------+');
END {Menu};

PROCEDURE Main_Loop();
VAR
        Option : CHAR;

BEGIN
        Option := 'd';
   WHILE Option <> 'q' DO
       BEGIN
            CASE Option OF
               'L' : yylex();
               'P' : yyparser(Tokens);
               'l' : Menu();
               's' : Menu();
               'r' : Menu();
               'd' : Menu();
              ELSE
                  Menu();
              END;

       WRITE('Type your command: ==> ');
      READLN(Option);
 END
END {Main_Loop};



BEGIN
   Main_Loop();
END. {LexDemo}