<textarea id="editor1" name="editor1">This is sample text</textarea>
<div id="trackingDiv" ></div>
<script type="text/javascript">
CKEDITOR.replace( 'editor1' );
</script>
Let try this..
Update :
To set data :
Create instance First::
var editor = CKEDITOR.instances['editor1'];
Then,
editor.setData('your data');
or
editor.insertHtml('your html data');
or
editor.insertText('your text data');
And Retrieve data from your editor::
editor.getData();
If change the particular para HTML data in CKEditor.
var html = $(editor.editable.$);
$('#id_of_para',html).html('your html data');
These are the possible ways that I know in CKEditor