A circuitized substrate and method of making same in which a first plurality of holes are formed within two bonded dielectric layers and then made conductive, e. Also set forth is a method for verifying correct receipt of the test messages and reporting the verification results. Next, determine if the first tracking error signal is correct or not: if yes, continue to use the first tracking error detecting method, otherwise, change to the second tracking error detecting method. The gases are kept separate by a divider in the tank. During the act of touching the screen, the lamina of light in the free space adjacent the screen is interrupted. A floor may be formed by placing a number of panels together, and the floor panels may be mounted on a matrix of beams which are themselves mounted on height adjustable pedestals.