Each time an operator logs in to the Trouble Ticket Express, the system inserts an html code that results in downloading an image from our web site. Depending on version reported the image is either "latest version" or "update available". The image is relatively small, it is inserted in the page footer and may be outside of visible page area.

The security alert notification must use the same technique, but

• to be inserted at the top of a page
• to be requested frequently (more than once per session)