CKEditor on hidden Div

Question

I'm developing a responsive website with 2 CKEditors. One CKEditor is visible and other is hidden:

<div id="mainWebContainer" >
<div id="mainWebContainerBox">
  <textarea name="ck1" id="ck1" rows="10" cols="80" > </textarea>
</div>
</div>

<script type="text/javascript">
CKEDITOR.replace( 'ck1', {....});
</script>

<div id="mainMobileContainer" >
<div id="mainMobileContainerBox">
  <textarea name="ck2" id="ck2" rows="10" cols="80" > </textarea>
</div>
</div>

<script type="text/javascript">
CKEDITOR.replace( 'ck2', {....});
</script>

where mainWebContainer is visible and mainMobileContainer is hidden. The problem is that, CKEditor on hidden div is initialized, but is not shown and then when the div is visible CKEditor is not showed.

How to resolve the problem? There is a solution? There is antorher solution?

Thanks a lot