Inhalation of low levels of nitric oxide can rapidly and safely decrease pulmonary hypertension in mammals. The system includes a plurality of display computers where each display computer is operatively connected to one of the display monitors for providing video or other digital content information to the display monitor to be displayed. A ticket issuer executing on a first computing device generates the web ticket responsive to receiving authentication data from a client computing device, and transmits the web ticket to such client computing device. Digital data are exchanged through the communication line between electronic control unit and monitoring circuit.