CKEDITOR NOT LOADING IN DIV

Hello I am new to CKEDITOR, I created a page, and on click of a link am loading the CKEDITOR page into a DIV using ajax, on the first load the editor shows up, but when I click the link again say after I am done, checked another page then click the link again to continue work, the CKEDITOR doesn't show up.

See sample code below
The LINK : <a href="#" onclick="getpage('edit_content.php','content')">Vision & Mission</a>

The CKEDITOR Page:
<div id="edit_content">
<textarea class="ckeditor" cols="80" id="editor1" name="editor1" rows="10"><p>This is some <strong>sample text</strong>. You are using <a href="http://ckeditor.com/">CKEditor</a>.</p></textarea>
<script type="text/javascript">
CKEDITOR.replace( 'editor1' );
</script>
</div>

When I click on the Link, the CKEDITOR page loads into the 'content' DIV of the main page. If I click on another link and now click the LINK again, the CKEDITOR doesn't load into the DIV again, rather I have the TEXTAREA just displaying.