var
aChar: array [1..26] of char= ('a','b','c','d','e','f','g','h','i',
                        'j','k','l','m','n','o','p','q','r',
                        's','t','u','v','w','x','y','z');

var
  i:word;
begin
  randomize;
  i:=random(26);
  showmessage(achar[i]);