Harmless Javascript Error?

Hey I just found the solution in a thread by ssharma :-

The problem is fixed by commenting following two lines in the fckeditor.html file.

<!-- <script language="javascript" src="/fckeditor.config.js"></script> -->

<!-- <script language="javascript" src="/fckeditor.custom.js"></script>-->

These two javascript files are missing or probably we have to create them in order to customise the editor.