validation doesn't seem to be working properly

validation doesn't seem to be working properly

Hello, I have a problem with validation plugin. It was working but now it doesn't. I don't know why this has been happened. the question is on stack-overflow.


and here is the code that I have written.
  2. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
  3. <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">

  5. <head>
  6.  <meta http-equiv="content-type" content="text/html; charset=utf-8" />
  7.   <title>Form</title>
  8.   <script src="lib/jquery.js" type="text/javascript"></script>
  9. <script src="lib/jquery.metadata.js" type="text/javascript"></script>
  10. <script src="jquery.validate.js" type="text/javascript"></script>

  12. <script type="text/javascript">

  14. $.metadata.setType("attr", "validate");

  16. $(document).ready(function() {
  17. $("#form1").validate({
  18. messages: {
  19. checkbox1: {required: 'you must agree'}
  20. }
  21. }
  22. );
  23. });
  24. </script>

  26. </head>

  28. <body>
  29. <div id="apDiv1">
  30. <h1 style="text-align:center">STEP ONE</h1>
  31. </div>
  32.   
  33.   <form  id="form1" action="action.php"  method="post">

  35.      Enter Your Number
  36.         <label>
  37.           <input name="textfield1" type="text" id="textfield1" />
  38.         </label>
  39.  
  40.   <p/>
  41.  I agree
  42.  <input type="checkbox" name="checkbox1" id="checkbox1" validate="required:true"/>

  44.      <p/>   
  45.     <input type="submit" name="submit" value="Next"  />
  46.   

  48.   </form>

  50. </body>

  52. </html>




Thank you in  advance.