uses crt;
function minuscula(txt: string): string;
var i: integer;
Begin
for i:=1 to length(txt) do
Begin
if (ord(txt[i])>=65) and (ord(txt[i])<=90) then
Begin
txt[i]:=chr((ord(txt[i])+32));
End
else
Begin
case txt[i] of
'Á': txt[i]:='a';
'É': txt[i]:='e';
'Í': txt[i]:='i';
'Ó': txt[i]:='o';
'Ú': txt[i]:='u';
'Ñ': txt[i]:='ñ';
end;
end;
End;
minuscula:=txt;
End;
Begin
clrscr;
gotoxy(2,2);write('Ingresa una cadena: ');
readln(cad);
cad:=minuscula(cad);
gotoxy(2,5);write('Se ha transformado la cadena en minuscula:');
gotoxy(2,7);write(cad);
readkey;
End.