function toggleLayer(id){ 
   if (document.getElementById){ 
   var el = document.getElementById(id); 
   el.style.display = (el.style.display == 'none') ? 'block' : 'none'; 
   } 
   }
   
   
   function form_Validator(form)
   {
   
   if (form.reac_naam.value == "")
   {
   alert("U dient uw naam in te geven.");
   form.reac_naam.focus();
   return (false);
   }
   
   if (form.reac_tekst.value == "")
   {
   alert("Het reactie veld mag niet leeg zijn.");
   form.reac_tekst.focus();
   return (false);
   }
   
   return (true);
   }
   
   function textCounter(field, countfield, maxlimit) {
   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;
   }