Karakter Sayıcı (Character Counter)

// ***********************************************
// 1.  HEAD bölümüne eklenecek kodlar
// ***********************************************
<script type="text/javascript">
<!--
function getObject(obj) {
  var theObj;
  if(document.all) {
    if(typeof obj=="string") {
      return document.all(obj);
    } else {
      return obj.style;
    }
  }
  if(document.getElementById) {
    if(typeof obj=="string") {
      return document.getElementById(obj);
    } else {
      return obj.style;
    }
  }
  return null;
}

//Contador de caracteres.
function Contar(entrada,salida,texto,caracteres) {
  var entradaObj=getObject(entrada);
  var salidaObj=getObject(salida);
  var longitud=caracteres - entradaObj.value.length;
  if(longitud <= 0) {
    longitud=0;
    texto='<span class="disable"> '+texto+' </span>';
    entradaObj.value=entradaObj.value.substr(0,caracteres);
  }
  salidaObj.innerHTML = texto.replace("{CHAR}",longitud);
}
//-->
</script>

// ***********************************************
// 2.  BODY bölümüne eklenecek kodlar
// ***********************************************

<form action="#" method="post">
<table align="center" class="0" border="0" cellspacing="1" cellpadding="5">
  <tr>
    <td align="right" class="1"><span class="options">Field Name</span></td>
    <td class="2"><INPUT TYPE="TEXT" class="text" id="eBann" name="bannerURL" maxlength="100" size="60" onKeyUp="Contar('eBann','sBann','{CHAR} characters left.',100);"><br><span id="sBann" class="minitext">100 characters left.</span></td>
  </tr>
</table>
</form>