The present invention is directed towards the synthesis of novel and new chloropyridine skeleton based compounds and these are Bayllis Hillman adducts having a remarkable in vitro anti-malarial activity. An N-bit adder adds a video signal and an upper-N-bit signal of a brightness control signal as an offset value. The multiple messaging communications systems use a plurality of associated messaging clients on each of the users’ respective devices, for messaging communications between the users. The integral signal is proportional to the output signal in a first operational mode. The lock mechanism selectively restrains the headrest portion from moving from the forward position to the rearward position.