function limitText(limitField, limitCount, limitNum) 
{
    if (limitField.value.length > limitNum) 
    {
        limitField.value = limitField.value.substring(0, limitNum);
    } 
    else 
    {
        limitCount.value = limitNum - limitField.value.length;
        document.getElementById("countdown").innerHTML = limitNum - limitField.value.length;
    }
}