The top left navigation region contains a home button, an about SHOW button (which should be replaced with an 'Other SHOW Sites' button on all sites other than the main SHOW website), a help button and a comments button.
The Home button always returns the user to the first page of the current site. Another button depicting an upwards pointing arrow may also be present, depending on how the site providers have chosen to implement the site. Where present, this button will go back (or up) to the last accessed Web site before the one being currently accessed. If the "up" button is present, the action of the Back button will be to go back through the previously accessed pages on the current site until the Home page is reached. This prevents users from inadvertently leaving the current site.
The help button brings users to this help site. The comments button lets users send email comments to those responsible for a site. The about SHOW button on the main SHOW website provides information on the workings of SHOW. On all other SHOW hosted sites this should be replaced by an 'Other SHOW Sites' button that will link back to the SHOW homepage.