procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
if not(Key in ['0'..'9',#8]) then
begin
Key:=#0;
BEEP;
end;
end;
procedure TForm1.Edit1Change(Sender: TObject);
begin
If Edit1.Text[1]='0' then
begin
ShowMessage('El primer valor no puede ser cero.');
Edit1.Text:=Copy(Edit1.Text,2,Length(Edit1.Text));
end;
end