Surely you mean Word2003 and not Word v. 3!
Word doesn't really know about "pages." You could select the text on
p. 5, Cut it, and Paste it after p. 7.
If each "page" begins with a specific Heading style, you can switch to
Outline view, Collapse the view so that only that Heading level shows,
and drag the heading of p. 5 to after the heading of p. 7; all the
text under the heading goes with it.