I am creating a list of images which links to areas of a website. Each image is hosted within the area of the site it is linking to. The issue I am having is not all users on my site can access all areas and so; is it possible to check if an image is available (or exists). If it is, display the image and some HTML to wrap it in, if it isn't, display a different image (again, wrapped in some HTML). Any advice would be greatly appreciated. Thanks in advance.