If your client is selling photos, then I suggest you put thumbnails of the
images (not high quality images) and/or water-mark the images so that the
watermark can't be removed, and anyone copying the images would have a copy
that they can't use.
Then if they want that print, they can order it through whatever means
you're providing to the client. (e.g. e-commerce etc).
In anycase, even if you had the no-right-click script in action, it can be
easily worked around
1) use the File > Save As menu
Additionally,
2) Everything you view on the net is downloaded first before being displayed
in your browser - essentially everything is copied to your computer first
anyway, so there's no point to the no right click function (that's what the
'web cache' and 'temporary internet folders are for).
3) Even though the no right click script would prevent "View Source" from
that context menu, View Source is also available for the standard menu
"View" - and probably available on most browsers
4) Don't expect those no right click scripts to work in all browsers - the
script would be useless where it doesn't work
5) These types of scripts are javascript - many people have javascript
disabled - so again the script is useless.
6) Disabling no right click is a pain - the context menu contains more
options than "View Source" and "Save Image As".