Maybe final version

program Project2;
{$APPTYPE CONSOLE}
uses
  System.SysUtils;
var
   IsInvalid, HasAllLetters: Boolean;
   Alphabet : set of 'A'..'z';
   Name : String;
   i : Integer;
begin
   Alphabet  := ['A'..'z'];
   IsInvalid := True;
   HasAllLetters := True;
   Writeln('This program can recognize and greet one of 5 friends');
   while IsInvalid do
      try
         Writeln('Enter your shortened name');
         Readln(Name);
         for i := 1 to Length(Name) do
            if not (Name[i] in Alphabet) then
               HasAllLetters := False;

         if HasAllLetters 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;

   if Name = 'Lynn' then
      Writeln('Hello Carolyn!')
   else
      if Name = 'Mike' then
         Writeln('Hello Michael!')
      else
         if Name = 'Bob' then
            Writeln('Hello Robert!')
         else
            if Name = 'Liz' then
               Writeln('Hello Elizabeth!')
            else
               if Name = 'Peg' then
                  Writeln('Hello Margareth!')
               else
                  Writeln('I DON''T KNOW YOU!');
   Readln;
end.