Проверка вхождения в массив букв

Const
  DataBaseFileName = 'lab3.db';
  MaxTeacherNameLength = 100;
  MaxdepNameLength = 20;
  ActionNewRecord = 1;
  ActionSortedList = 2;
  ActionExit = 3;
 
Type
  TTeacher = Record
    name: String;
    department: string;
    mark: real;
  end;
  TTeacherArray = Array [1..1] of TTeacher;
 
Var
  answer: Char;
  f: File;
  db: ^TTeacherArray;
  recordsCount,a, i,j,action, memSizeOnStart: Integer;
  tmp:real;
  tempstring,str: string;
 
Procedure HandleCannotAddRecord;
begin
  Assert(false, 'Не получается добавить запись в файл');
  WriteLn('Cannot add record to ' + DataBaseFileName);
end;
 
Procedure  ErrorWrite;
Var
  tempRec: TTeacher;
  count_name,count_department,count_mark: integer;
begin
  for count_name := 1 to Length(tempRec.name) do
  if (tempRec.name[count_name] in ['0'..'9']) or (tempRec.name  = '')
  or (tempRec.name = ' ') then
    begin
      WriteLn('Name teacher have a digits or any sybols');
      Exit;
    end;
  for count_department := 1 to Length(tempRec.department) do
    if (tempRec.department[count_department] in ['0'..'9']) or (tempRec.department  = '')
    or (tempRec.department = ' ') then
      begin
        WriteLn('department have a digits or any sybols');
        Exit;
      end;
  for count_mark := 1 to  Length(tempRec.mark) do
    if tempRec.mark[count_mark] in ['A'..'Я'] or  (tempRec.mark  = '') then
      begin
        WriteLn('mark have a words or any sybols');
        Exit;
      end;

if (tempRec.mark[count_mark] in ['A'..'Я']) or  (tempRec.mark  = '') then

or  (tempRec.mark  = ' ') then