program pin;
uses
   crt;
var
   PinNumber: string;
   Done: Boolean;
   ACharacter: Char;
begin
   { Initialize variables. }
   Done := False;
   PinNumber := '';
 
   { Prompt user for input. }
   writeln;
   write('Enter your pin number: ');
 
   { Read input. }
   repeat
      ACharacter := ReadKey;
      case ACharacter of
         '0'..'9':
            begin
               write('*');
               PinNumber := PinNumber + ACharacter;
            end;
      else
         Done := True;
      end;
   until Done;
 
   { Display pin number. }
   writeln;
   writeln('Your pin number is: ' + PinNumber);
end.

program names;
uses
   SysUtils;
const
   DataFileName = 'C:\NAMES.TXT';
var
   DataFile: TextFile;
   FirstName: string;
   LastName: string;
begin
   { Prompt user for first name. }
   write('Enter your FIRST name: ');
   readln(FirstName);
 
   { Prompt user for last name. }
   write('Enter your LAST name: ');
   readln(LastName);
 
   { Open the file. }
   AssignFile(DataFile, DataFileName);
   if FileExists(DataFileName) then
   begin
      Append(DataFile);
   end
   else
   begin
      Rewrite(DataFile);
   end;
 
   { Write data to the file in comma delimited format. }
   writeln(DataFile, LastName + ',' + FirstName);
 
   { Make sure the file is written to disk, then close it. }
   Flush(DataFile);
   CloseFile(DataFile);
end.