What that does is insert a Border.
You can remove it via the Borders and Shading dialog.
To prevent it from happening go to the AutoFormat As You Type tab of the
AutoCorrect dialog and unchec the "Border Lines" item
in the Apply as you type section of the dialog.
In versions of Word before 2007, the AutoCorrect dialog is on the Tools
menu; In Word 2007, you access it via Word Options, Proofing.
--
Hope this helps,
Doug Robbins - Word MVP
Please reply only to the newsgroups unless you wish to obtain my services on
a paid professional basis.