The setting you want isn't Page Break Before, but Keep With Next. When
Word would otherwise put an automatic page break between paragraphs A
and B, if paragraph A has Keep With Next, then both paragraphs go to
the next page.
First, remove the Page Break Before from the Heading 1 style. While
you're in there, verify that Keep With Next is checked (it is, by
default, for all the Heading N styles for levels 1 to 4).
Whatever style you used for the remaining lines of each entry, modify
that style so it also has Keep With Next. You probably don't want to
do this for all documents, so don't check the Add To Template box in
the Modify dialog, and the change will affect only the current
document. (Whatever you do, don't check the "Automatically update" box
in that dialog -- that one's a killer!)
Now you have to allow page breaks between entries, by removing the
Keep With Next from the last line of each entry. You could go through
the document doing this by hand, but there's an easier way. First
define a new style that's based on the regular text's style, but
remove the Keep With Next. To apply that style to the right paragraphs
(assuming that only zip codes contain five consecutive digits):
- Open the Edit > Replace dialog.
- In the Find What box, enter
^#^#^#^#^#
- In the Replace With box, enter
^&
- Click the More button and then the Format button, and select Style
from the popup menu. Choose the style you created for the last line
and click OK. Then click the Replace All button.