I try add text at the end of the document but it doesn't work.
My code:
function PasteHTML(html)
{
   // get the cute editor instance
   var editor1 = document.getElementById('<%=Editor1.ClientID%>');
   // get internal editor document
   var editdoc = editor1.GetDocument();
   // get default view of internal document
   var defView = editdoc.defaultView;               
   // insert of text
   editor1.PasteHTML(html);
   // trying scroll document
   defView.scroll(0, 222000);
   editor1.FocusDocument();
}