function textCounter(aField, aCountfield, maxlimit) {
    field = document.getElementById(aField);
    countfield = document.getElementById(aCountfield);
    if (field.value.length > maxlimit) // if too long...trim it!
        field.value = field.value.substring(0, maxlimit);
    // otherwise, update 'characters left' counter
    else 
        countfield.value = maxlimit - field.value.length;
}