i need to know how do you make somebody not copy pictures from your
homepage?
With great difficulty unless you remove them.
You could tell them that it is illegal according to the Berne Convention
regarding literary and artistic works and, as I understand it, the
Trade-Related Aspects of Intellectual Property Rights (TRIPS) agreement[1].
You can add watermarks and copyright text to your images in a way that is
difficult to remove.
You can also provide images at a substandard quality or small size that
will discourage their theft.
None of these will be 100% effective, though.
when they right click an error message comes on
That's useless and won't work in all cases anyway (it certainly won't in
my browser). You have to realise that once the user has downloaded your
image by viewing your page, it's on their computer and there are many ways
for them to take it. Disabling the context menu will only frustrate law
abiding users, and do nothing to stop the ones that are out to take your
work.
Mike
[1] Obviously, it doesn't mean much unless you can prove that your work
was taken in violation of the provisions of those agreements, that they
apply to the perpetrator, and that you're willing to take the case to a
court with appropriate jurisdiction. Pretty much impossible, really.