<script language="Javascript"> var countdown; var countdown_number; function countdown_init() { countdown_number = 11; countdown_trigger(); } function countdown_trigger() { if(countdown_number > 0) { countdown_number--; document.getElementById('countdown_text').innerHTML = countdown_number; if(countdown_number > 0) { countdown = setTimeout('countdown_trigger()', 1000); } } } function countdown_clear() { clearTimeout(countdown); } if (countdown_number == 0) { //здесь события которое делает кнопку активной } </script> <div id="ren"> <input type="button" value="старт" onclick="countdown_init(), this.disabled = true;" /> <input type="button" value="стоп" onclick="countdown_clear()" /> </div> <div id="countdown_text">qwe</div>