Apart from Kino's macro DocComp, which has options to compare by paragraph,
clause or word, and which creates a diff file, there is another macro of
his, 'CompareTwoWindows', which stops the cursor at every difference in
either file, allowing you to make on the fly changes. This macro detects
even invisible characters.

Here is the download link:

http://www2.odn.ne.jp/alt-quinon/files/NWPro/misc/CompareTwoWindows-nwm.zip

I must thank Kino for this extremely useful macro.

Hamid