jQuery BlockUI不会关闭

Question

无法关闭我的BlockUI对话框。我已经使用相同的技术实现了其中几个，但是这个似乎似乎没有因为某些原因触发click事件：

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
  ...
  <script src="jquery.blockUI.js" type="text/javascript"></script>
  ...
</asp:Content> 

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">

  ...

  <div id="dialogUnpaidLandlord" style="display: none">
    <div style="cursor: default; padding: 1em; font-family: arial; font-size: 0.9em; text-align: left; line-height: 1.5em">
      <div style="font-size: 1.5em; margin-bottom: 1em; font-family: arial;"blah blah...</div>

      <div style="text-align: right; padding-bottom: 1em;">
        <span id="spnLNoThanks" class="notnowthanks" style="margin-right: 1em">
          not now thanks
        </span>
        <span class="divbutton" style="margin-right: 1em">
          <asp:HyperLink ID="HyperLink1" runat="server" style="text-decoration: none; color: white" NavigateUrl="~/ss.aspx">pay now</asp:HyperLink>
        </span>
      </div>
      </div>
  </div>


    <script type="text/javascript">
    $('.notnowthanks').click(function() {
      $.unblockUI();
      return false;
      });


    </script>

</asp:Content> 

任何想法？