During communications sessions between an agent in a call center and a customer, it is often desirable that a secondary agent is consulted, the secondary agent perhaps more suited to the particular needs of the customer. The present invention generates a set of selection identifiers on the basis of a user-provided first input identifier and determines which of these selection identifiers are present in a set of pre-stored reference identifiers. The divided voltages are supplied as an internal power voltage to a plurality of field effect transistors incorporated into the semiconductor chip.