title: Unable to get/set contents of tiny mce editor
body: <p>I am using Tiny MCE editor version : 3.5.7<br>
  I am using multiple instances of text editor on same page with unique IDs and I have wrapped these editors in a div to show and hide these editors. Everything was working fine. Now I want to clear the contents of the editor when user hide it (so that when it is displayed again the previous contents are removed). I tried to do it using <strong>tinyMCE.get('editorId').setContent('')</strong>, it works fine only once.... I mean once I  have used the above function than I am unable to <strong>set</strong> or even <strong>get</strong> the contents of that editor instance. The structure that I have used is as follows:</p>
  
  <pre><code>&lt;div id="parentDIV"&gt;
    &lt;div id="1_editor"&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  
  tinyMCE.init({
          mode: "exact",
          max_char: "2000",
          elements: "1_editor",
          // Setting up ToolBar
          theme: "advanced",
          theme_advanced_layout_manager: "SimpleLayout",
          theme_advanced_buttons1: "bold,italic,underline, strikethrough,     separator,justifyleft, justifycenter,justifyright,  justifyfull, separator,bullist,numlist,separator,fontselect ,fontsizeselect",
          theme_advanced_toolbar_location: "top",
          theme_advanced_toolbar_align: "left",
      });
  </code></pre>
  
  <p>To show and hide the editor I doing something like this:</p>
  
  <pre><code>$('#parentDIV').hide();
  $('#parentDIV').show();
  </code></pre>
  
  <p>Can anyone help please?</p>