Can I stop a server removing the www. prefix ?

When accessing a website (on a third party server - so my scope for
modifying the configuration is limited) in some circumstances
the "www." prefix gets removed.

These circumstances appear to be:

if I access http://www.mysite.co.uk/index.html the page loads and the
address bar shows exactly that.

if I access http://www.mysite.co.uk/ the index page loads and the
address bar shows exactly that.

if I access http://www.mysite.co.uk (i.e. no trailing slash or
filename) the index page loads and the address bar shows
http://mysite.co.uk/ (i.e. the trailing slash has been added but the
www. prefix has gone).

This is causing the Ecommerce package I use some difficulties with
Cookies.

Suppose a cookie is written when the site address is www.mysite.co.uk

If this is later accessed by an address without the www. prefix (i.e.
mysite.co.uk) the cookie data seems to get out of step by 4 characters
and is effectively unusable.

Is there any way to force the server to translate any accesses to
mysite.co.uk/... to become www.mysite.co.uk/... or to prevent the
server changing http://www.mysite.co.uk to http://mysite.co.uk/

I think using rewrite engine in htaccess might offer an answer, I've
had a go without success (possibly because I'm struggling to
understand the rewrite syntax - is there a complete idiot's guide
anywhere?).

<shortbackandsides.no RemoveThis @spam.hairdresser.net> wrote in message
news:vua6b01fnro792k8mb6n7utm4565v9f8ga@4ax.com...
 > When accessing a website (on a third party server - so my scope for
 > modifying the configuration is limited) in some circumstances
 > the "www." prefix gets removed.
 >
 > These circumstances appear to be:
 >
 > if I access <a style='text-decoration: underline;' href="http://www.mysite.co.uk/index.html" target="_blank">http://www.mysite.co.uk/index.html</a> the page loads and the
 > address bar shows exactly that.
 >
 > if I access <a style='text-decoration: underline;' href="http://www.mysite.co.uk/" target="_blank">http://www.mysite.co.uk/</a> the index page loads and the
 > address bar shows exactly that.
 >
 > if I access <a style='text-decoration: underline;' href="http://www.mysite.co.uk" target="_blank">http://www.mysite.co.uk</a> (i.e. no trailing slash or
 > filename) the index page loads and the address bar shows
 > <a style='text-decoration: underline;' href="http://mysite.co.uk/" target="_blank">http://mysite.co.uk/</a> (i.e. the trailing slash has been added but the
 > <a style='text-decoration: underline;' href="http://www." target="_blank">www.</a> prefix has gone).
 >
 > This is causing the Ecommerce package I use some difficulties with
 > Cookies.
 >
<font color=purple> > Suppose a cookie is written when the site address is <a style='text-decoration: underline;' href="http://www.mysite.co.uk</font" target="_blank">www.mysite.co.uk</font</a>>
 >
 > If this is later accessed by an address without the <a style='text-decoration: underline;' href="http://www." target="_blank">www.</a> prefix (i.e.
 > mysite.co.uk) the cookie data seems to get out of step by 4 characters
 > and is effectively unusable.
 >
 > Is there any way to force the server to translate any accesses to
 > mysite.co.uk/... to become <a style='text-decoration: underline;' href="http://www.mysite.co.uk/..." target="_blank">www.mysite.co.uk/...</a> or to prevent the
<font color=purple> > server changing <a style='text-decoration: underline;' href="http://www.mysite.co.uk" target="_blank">http://www.mysite.co.uk</a> to <a style='text-decoration: underline;' href="http://mysite.co.uk/</font" target="_blank">http://mysite.co.uk/</font</a>>
 >
 > I think using rewrite engine in htaccess might offer an answer, I've
 > had a go without success (possibly because I'm struggling to
 > understand the rewrite syntax - is there a complete idiot's guide
 > anywhere?).
 ><!-- ~MESSAGE_AFTER~ -->