var maxchars = 500;

     function check_length()
     {
       var message = document.getElementById('description');
       var len = message.value.length;

       if (len > maxchars) {
         message.value = message.value.substr(0,maxchars);
         len = maxchars;
       }

       document.getElementById('wordcount').innerHTML = len;
       document.getElementById('remaining').innerHTML = maxchars - len;
     }