// counter
function txtCounter(q_additional, countfield, maxlimit) 
{
if (document.mainform.q_additional.value.length > maxlimit) 
// if too long, trim it
document.mainform.q_additional.value = document.mainform.q_additional.value.substring(0, maxlimit);
// otherwise, update 'characters left' counter
else 
countfield.value = maxlimit - document.mainform.q_additional.value.length;
}