A system may receive a video asset from a content provider. The pad has elasticized side panels which comprise at least two layers of non-woven material mounted between a cover and baffle, projecting beyond the side edges of the cover and the baffle, giving the panel soft, free outer distal edges and one or more elastic members inboard from the free distal edge. The surfactant is preferably represented by the, formula X\u2212 wherein R is an alkyl group of 1 to 22 carbon atoms, a fluoroalkyl group obtainable by fluorine substituting at least a part of hydrogen atoms present in the above alkyl group or hydrogen, four R’s may be the same or different provided that they are not hydrogen atoms simultaneously, and X is a halogen atom. A first converter calculates a brightness and color difference signals from red, green, blue video signals to be displayed in the display panel. The substitute certificate is signed by the authentication server and used for authentication and communication with principals that have knowledge of and trust the authentication server. At least one of the plurality of optical elements of the optical assembly is selected from among a plurality of ones selectable from the interchange mechanism which facilitates exchange of one for another in the beam path.