No action has to
be taken to establish copyright over a piece of original work. This
is a general principle applicable worldwide. The copyright is owned
by the creator unless he chooses to assign it to others.
However, it is rather
more difficult to defend your copyright if someone chooses to copy your
There are some steps
you can take:
1) add the expression
Copyright or © to the work, to make it clear that you do not want
it copied, and may take action against those that do
2) if you have particularly
precious piece of work (eg: a company logo or image) then you can post
it to yourself by registered post. This can act as evidence in legal
proceedings, to help establish that you created the work before others.
A key point with
web site design is that if you commission another organisation to develop
the software, they have the copyright. You should ensure that they agree
to assign you copyright or that they licence you to use it in perpetuity
for no charge. If you do not do this, then there is a (small) chance
that they could deny you use of it subsequently.