void rightax (yright) SVC.C Level 1
int yright  = 1 to turn on right-hand y axis.
 = 0 to turn off right-hand y axis.
rightax() is a parameter setting routine that will cause GraphiC to draw a right-hand y axis. When this flag is set, the first time scales() or graf() is called the left-hand y axis and the x axis will be drawn. With a second call to scales() 
or graf() the program will rescale and draw a second y axis on the right end of the x axis. This is done without recalculating or redrawing the x axis.