How to get the active/focused editor from multiple editors?

Hi
Have many editors on a page. I want to InsertHtml() in the editor the user is currently writing in.
How can I get the correct editorinstance?

I used this in fckeditor:

function FCKeditor_OnComplete( editorInstance )
                    {
                        editorInstance.Events.AttachEvent( 'OnFocus', setFocusedEditor ) ;
                    }

                    function setFocusedEditor(editorInstance) {
                        document.getElementById("focusedEditor").value = editorInstance.Name;
                    }

Then I have the name of the editor in a hidden field (<input type="hidden" id="focusedEditor"....) and can insert the html in the correct editor.

How to do this with CKEditor?