function textBoxCounter(inputField, counterField, maxLength)
{
  var cField;
  
  if (document.layers)
  {cField = document.layers[counterField];}
  else if (document.all)
  {cField = document.all[counterField];}
  else if (document.getElementById){cField = document.getElementById(counterField);}
  
  if (inputField.value.length > maxLength) 
    inputField.value = inputField.value.substring(0, maxLength);
  else cField.innerHTML = maxLength - inputField.value.length;
 }