<script type="text/javascript" src="http://code.jquery.com/jquery-1.8.2.js"></script>
<script>
function ekle(){
var mesajlar = $('input[name=mesaj]').val();
alert(mesajlar);
}
</script>
<?php
/**
* @author Lithack
* @copyright 2012
*/
?>
<input type="text" name="mesaj" onkeypress="ekle()"/>