How to refresh layout in window

[chiefer]

I create a window includes 2 layout, north and center.When I open the window 'win_address_shipping', the layout of 'north' can get remote data.I still have a button in the window and bind 'click' event to refresh the 'north' layout, not the whole window 'win_address_shipping'.
Below is the window html code:
<div id="win_address_shipping" class="easyui-window" title="Address & Shipping Management" style="width:600px;height:430px" data-options="collapsible:false,maximizable:false,minimizable:false,closed:true" >
  <div class="easyui-layout" data-options="fit:true">
    <div data-options="region:'north',split:true" style="height:230px;overflow:auto;" href="ajax_user_address.php"></div>
    <div data-options="region:'center'" style="overflow:auto;"><div id="pop_address_box"></div></div>
  </div>
</div>

[stworthy]

To refresh a region panel's content, get the region panel and then call 'refresh' method on it.

Code:

var p = $(...).layout('panel','north');  // get the north panel
p.panel('refresh');  // refresh the panel content

[chiefer]

I also wirte like this, but it reported the following error

--------------------------------------------------------------------------------------
Uncaught TypeError: Cannot read property 'panels' of undefined jquery.easyui.min.js:4372
$.fn.layout.methods.panel jquery.easyui.min.js:4372
$.fn.layout jquery.easyui.min.js:4350
(anonymous function) wholesale.js:1062
p.event.dispatch jquery-1.8.0.min.js:2
g.handle.h
--------------------------------------------------------------------------------------

[chiefer]

I used jQuery EasyUI 1.3.2

[chiefer]

I used another way to solve this problem. I set ID to the north, the ID is 'pop_address_list_box'

<div id="win_address_shipping" class="easyui-window" title="Address & Shipping Management" style="width:600px;height:430px" data-options="collapsible:false,maximizable:false,minimizable:false,closed:true" >
  <div class="easyui-layout" data-options="fit:true">
    <div data-options="region:'north',split:true" style="height:230px;overflow:auto;" href="ajax_user_address.php" id="pop_address_list_box"></div>
    <div data-options="region:'center'" style="overflow:auto;"><div id="pop_address_box"></div></div>
  </div>
</div>

js code is
$('#pop_address_list_box').panel({
   href:'ajax_user_address.php?action=pop_address_shipping'
})