window.onload = init; 
  function init() { 
    document.getElementById('countArea').innerHTML = 200-document.getElementById('text').value.length; 
  } 

  function updateCounter(field,maxlength,id,counter) {
    var totalLength = field.value.length; 
    if(totalLength >= maxlength) {
      field.value = field.value.substring(0, maxlength);
    }
    document.getElementById(counter).innerHTML = maxlength-field.value.length;
  }