default value for a new instance

ciao!
till a bit time ago i do this in ASP

<%

dim editor1
set editor1 = New CKEditor
 editor1.basePath = "ckeditor/"
 editor1.instanceConfig("skin") = "v2"
 response.write editor1.editor("content", content)

%>

now, due to the explorer update, my copy/paste don't work anymore, so i've upgraded my ckeditor with the last version (4.3)

everything fine for my ADD field with ckeditor into a form

but i've a problem with the EDIT... i mean... i don't know how to put my data as a default value in my ckeditor

now i've this situation

<textarea name="testo" id="testo" cols="45" rows="5"></textarea>
<script>
CKEDITOR.replace( 'testo' );
</script>

where i've to put my variables to give a default value to my input field?

thank you