Scott,

 

Please try the following code:

 

<script language="JavaScript" type="text/javascript" >
  var editor1=document.getElementById("<%=Editor1.ClientID%>");
  if(editor1.IsReady)CuteEditor_OnInitialized(editor);

  function CuteEditor_OnInitialized(editor)
  { 
   var editdoc = editor1.GetDocument();
   editdoc.attachEvent('onkeypress',function x(){return check(event);} );
  }

 

  function check(evt)
  {
   alert('keypressed');
   return true;
  }

</script>