How to get the value from from input text?

How to get the value from from input text?

  1. <html>
  2.     <head>
  3.         <title>jquery test</title>
  4.         <script type="text/javascript" src="js/jquery-1.8.2.js"></script>
  5.         <script type="text/javascript" src="js/jquery-ui-1.9.1.custom.js"></script>
  6. <!--   <script type="text/javascript" src="js/jquery.mobile-1.2.0.js"></script> -->
  7.         <link type="text/css" href="css/jquery-ui-1.9.1.custom.css" rel="stylesheet" >
  8.         <!--    <link type="text/css" href="css/jquery.mobile-1.2.0.css" rel="stylesheet" > -->
  9.         <script type="text/javascript">
  10.            
  11.             $(document).ready(function() {
  12.                 $('#id_div_dial').dialog();               
  13.             });
  14.            
  15.             $('id_input_submit').click(function() {
  16.                 temp = $('id_input_name').val();
  17.                 alert(temp);
  18.             })
  19.            
  20.         </script>
  21.     </head>
  22.     <body>       
  23.         <div id="id_div_dial" title="Basic Dialog">
  24.             <form id="id_form_basic" action=".">
  25.                 <input type="text" id="id_input_name" />
  26.                 <input type="button" id="id_input_submit" value="Submit"/>
  27.             </form>
  28.         </div>
  29.         <?php
  30.         echo 'Hello world';
  31.         ?>
  32.     </body>
  33. </html>

Typing something in input box if i click the button from from, it doesn't do anything. Why?
How can i get value from input textbox of that box?