Getting Text into Editor

Hi,

I am having some Text in a variable and wat to pass it to the editor window.
How can I do this?

I tried:
document.getElementById('CKEditor1').value = rarr[2] ;
CKEDITOR.instances.CKEditor1.updateElement();

But this is not working.

I am using a textarea named CKEditor1 and replace this one afterwards with CKEDITOR.replace('CKEditor1' ...).

Can anyone help me out how to get the text which is loaded via xmlhttp.responseText into a Javascript variable.

Here is the complete Code:

<textarea name="CKEditor1" id="CKEditor1" rows="8" cols="60></textarea>
<script type="text/javascript">
CKEDITOR.replace('CKEditor1', { "filebrowserBrowseUrl": "..\/..\/ckfinder.html", "filebrowserImageBrowseUrl": "..\/..\/ckfinder.html?type=fotos", "height": "100" });</script>
<h2><strong>VOLLTEXT</strong></h2><textarea name="CKEditor2" id="CKEditor2" rows="8" cols="60</textarea>
<script type="text/javascript">
CKEDITOR.replace('CKEditor2', { "filebrowserBrowseUrl": "..\/..\/ckfinder.html", "filebrowserImageBrowseUrl": "..\/..\/ckfinder.html?type=fotos", "height": "100", "toolbar": [ [ "Source", "-", "Bold", "Italic", "Underline", "Strike" ], [ "Image", "Link", "Unlink", "Anchor" ] ] });
</script>