An information recording medium comprises a substrate, a second recording layer, a second light transmitting layer, a first recording layer for recording different information from that to be recorded in the second recording layer, and a first light transmitting layer. Broadly contemplated are arrangements whereby jars or containers of new solution to be used in the calibration arrangement are subject to automatic verification. The source IP telephone transmits a call to the destination IP telephone by using the retrieved specific number. Fluctuations in these zero crossings makes phase of the reproduced clock unstable, which decreases error performance in an associated receiver. When the LCD panel is contacted, one or more internal piezoelectric elements respond to the pressure via one or more corresponding photo spacers and generate electrical signals.