[blackinwhite]

head kısmı

 <script type="text/JavaScript"><!--
 var limit = 500;
 function check() {
   if(document.form.box.value.length > limit) {
     alert('uff, çok oldu!');
     document.form.box.focus();
     return false; }
   else
     return true; }
 function update() {
   var old = document.form.counter.value;
   document.form.counter.value=document.form.box.value.length;
   if(document.form.counter.value > limit && old <= limit) {
     alert('Çok yazdınız!');
     if(document.styleSheets) {
       document.form.counter.style.fontWeight = 'bold';
       document.form.counter.style.color = '#ff0000'; } }
   else if(document.form.counter.value <= limit && old > limit
	   && document.styleSheets ) {
       document.form.counter.style.fontWeight = 'normal';
       document.form.counter.style.color = '#000000'; } 
   }
 //--></script>

body kısmı

<form action="submit.ASP" name="form" onsubmit="return check();"> 
<textarea rows="7" cols="40" name="box"
 onkeyup="update();"></textarea><br>
 <noscript>
 <p><small>(Browser'ınız JavaScript desteklemiyor.)</small>
 </noscript>
 <script type="text/JavaScript" language="JavaScript1.2"><!--
 document.write('Karakter sayısı: <input '+
  'type="text" size="3" name="counter" value=""'+
  'readonly onfocus="this.form.box.focus()"> (limit: '+
  limit+')');
 //--></script>
 <p><input type="submit" value="gönder">&nbsp; <input type="reset" value="temizle">
 </form>