I've installed CKEditor in the backend of my website. I've got the following problem when switching from code view to wysiwyg view. The code I'm inserting is like:

<div class="span4">
    <p>Some text here</p>
</div>

When I switch back to view mode CKEditor automatically removes the div surrounding the paragraph.

Can anyone please help me to remove this problem? I don't mind staying in code view but I do like working in the view mode for writing longer text.

Thanks in advance.

php javascript ckeditor
Edit
Report