Does web browser reload a page unnecessarily?

Question

This is an apparent feature of all Nokia web browsers I have so far used (in 6630, N80, N95, and N97): when I back off from a web page to any of the previous ones, the phone seems to reload the page again from the Internet, not just display it from the memory - at least it is apparent by the time it uses to the redisplay.
There can be a good reason for reloading, of course. Some pages may be so volatile that the contents may have changed. Most of the pages, even news sites, do not change _that_ frequently, however.
However, reloading from the Internet drains the phone battery. It also causes needless extra cost if you are roaming.

Answer 1

You can do it in script:
<script>
window.setTimeout("location.href = location.href", 5000);
</script>
You can also use a header in the page:
<%
response.setIntHeader("Refresh", 30)
%>
or to do the same in HTML
<META HTTP-EQUIV="Refresh" CONTENT="5; URL=http://host/path">
Cheers,
evnafets