how use jquery in response of jquery-ajax?

how use jquery in response of jquery-ajax?

hi friends. 
i am using jquery and jquery-ajax in my sample. but face problem.
i have three file. my file is :

jquery-1.8.3.min.js

index.html

res.html


jquery-1.8.3.min.js file is main of jquery file.
index.html code is :  

  1. <html>
  2. <head>
  3. <script type="text/javascript" src="jquery-1.8.3.min.js"></script>
  4. <script type="text/javascript">
  5. $(document).ready(function () {
  6. $.ajax({
  7. url: 'res.html',
  8. type: "POST",
  9. data: '',
  10. success: function (result) {
  11. $("#responsediv").html(result);
  12. }
  13. });
  14. });
  15. $(document).ready(function () {
  16. $('#state_id').change(function () {
  17. alert($(this).val());
  18. });
  19. });
  20. </script>
  21. </head>
  22. <body>
  23. <div id="responsediv"></div>
  24. </body>

  26. </html>
and res.html code is :
  1. <select id="state_id" name="state_id">
  2. <option value="1">first</option>
  3. <option value="2">second</option>
  4. <option value="3">third</option>
  5. <option value="4">forth</option>
  6. </select>

i don’t know why this code not runnig.

  1. $(document).ready(function () {
  2. $('#state_id').change(function () {
  3. alert($(this).val());
  4. });
  5. });

this is sample and simple code . i check this on another project and face this problem. thanks.
i ask this question in stackoverflow.com
but their answer don't help me.