javascript - jQuery adding custom password rule not working -

i new jquery , using jquery form validator validate form..

the problem , have validate password must contain at-least 1 digit..

i searched on google , found example in here link forum.jquery

here snippet of html code

  <form  name="f2" id="f2" method="post" action="hello">      <table>       <tr>              <th>                  password              </th>               <td>              <input type="password" name="pwd" id="pwd"  placeholder="enter password" class="text_box">               </td>       </tr>       <tr>            <td>               <button type="submit" class="submit-button">register</button>            </td>       </tr>       </table>     </form>      //jquery script form validation        <script>         $(document).ready(function(){             $("#f2").validate({                 debug: false,                 rules: {                    pwd:{                         required:true,                         minlength:5                     }                   },                 messages:                     {                       pwd:{                         required:"please enter password",                         minlength:"please enter minimum characters"                     }                  }              });         });     </script> 

everything works fine until add line above code rules

pwd:{     required:true,     minlength:5,     mypassword: true } 

i included additional scripting file contains following method

jquery.validator.addmethod('mypassword', function(value, element)  {     return this.optional(element) || (value.match(/[a-za-z]/) && value.match(/[0-9]/)); }, 'password must contain @ least 1 numeric , 1 alphabetic character.'); 

after trying execute above code, got following error message in browser console follows:

uncaught typeerror: cannot call method 'call' of undefined in js/jqueryvalidation.js

why additional method not working?

any or suggestions appreciated.

please check example in fiddler link : http://jsfiddle.net/naaew/

    jquery.validator.addmethod('mypassword', function(value, element)      {        return this.optional(element) || (value.match(/[a-za-z]/) && value.match(/[0-9]/));     }); 

and message :

    pwd:{                     required:"please enter password",                     minlength:"please enter minimum characters",       mypassword: 'password must contain @ least 1 numeric , 1 alphabetic character.' 

hope expecting.