Char case

program Project2;
{$APPTYPE CONSOLE}

uses
   System.SysUtils;

var
   IsInvalid: Boolean;
   Name: Char;
   Alphabet  : Set of 'A'..'z';

begin
   Alphabet  := ['A'..'Z'];
   IsInvalid := True;
   Writeln('This program can recognize and greet one of 5 friends');
   while IsInvalid do
      try
         Writeln('Enter your shortened name');
         Readln(Name);
         if Name in Alphabet then
            IsInvalid := False
         else
            Writeln('Error! Enter name (nonempty string, starts with uppercase letter)')
      except
         Writeln('Error! Enter name (nonempty string, starts with uppercase letter)');
      end;

      case ord(Name) of
         68 : writeln('Hello Danny!');
         77 : writeln('Hello Mike!');
         74 : writeln('Hello John!');
         82 : writeln('Hello Robert!');
         87 : writeln('Hello William!');
      else writeln('I DON''T KNOW YOU!');
      end;
   Readln;
end.