It is a common problem. See:

http://word.mvps.org/FAQs/Formatting...eformatted.htm


--
Greg Maxey/Word MVP
See:
http://gregmaxey.mvps.org/word_tips.htm
For some helpful tips using Word.

Patrick Henry wrote:
When I format one selected part of a Word document, the format change
is applied to the whole document. For example, if one phrase is
highlighted and made Bold, then the entire document is in Bold. If
one selected text is centered, the whole document is alligned to
center. Thank you.