Lines accross the page in 07

Hi

I've recently migrated to Word 2007 from Word 2003.

In Word 03 I could put '===' and a carriage return, and Word would put a
double line across the width of the page. The line would adjust
automatically if I changed the margin sizes etc. I could also use '###' and
'~~~' for different styles of line. (There were other styles too.)

This doesn't seem to work in Word 2007.

Can anyone tell me how to obtain these margin-to-margin lines in Word 07?

Grateful thanks in advance!