there is something wrong in click event

there is something wrong in click event



<!DOCTYPE html> 
<html>

<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1"> 
<title>Multi-page template</title> 
<link rel="stylesheet" href="http://code.jquery.com/mobile/1.2.0/jquery.mobile-1.2.0.min.css" />
<script src="http://code.jquery.com/jquery-1.8.2.min.js"></script>

<script src="http://code.jquery.com/mobile/1.2.0/jquery.mobile-1.2.0.min.js"></script>
</head> 

<body> 



  <textarea cols="40" rows="8" name="textarea" id="textarea_talk"></textarea>
         <input type="button" id="fabu" value="发布"  data-theme="a" data-mini="true" data-inline="true">
         <script>
           
               $( "#fabu" ).click(function(){
                    // alert("adadasd");
                    var a=$("#textarea_talk").val();
                    console.log(a);
                    return;
               });
           
         </script>
</body>
</html>

above is mypage, i want to out the value of textarea  once.but the result is twice .why???? who can help me ?