jquery mobile input masking not working
jquery.mobile-1.0.1.min.css
jquery-1.6.4.min.js
jquery.mobile-1.0.1.min.js

$("#ssnprimary").mask("999-99-9999");

<div data-role="page" id="mainpage">
    <div data-role="header">
      <h1> My Test </h1>
    </div><!-- /header -->

    <div data-role="content">
      <div class="content-primary">
        <form id="fmain" data-ajax="false">
          <!-- Primary SSN -->

          <div data-role="none">
            <label for="ssnprimary">SSN:</label>
            <input type="tel" name="ssnprimary" id="ssnprimary" value="" />
          </div>
          </form>
         <br />
       </div><!-- /content -->
    </div><!-- /content -->

    <div data-role="footer"
      data-theme="d"></div><!-- /footer -->
  </div><!-- /page one -->