In the following structures carbon atoms are dark gray, hydrogens are cyan and oxygen is red. The molecules are initially shown as mirror images, and can be moved by clicking on the structure and dragging the mouse. Holding the shift key during this operation allows zooming. To see the plane of chirality click the third button. The configuration is determined by viewing the chiral plane from the nearest out-of-plane atom (the pilot atom), chosen by the sequence rule if necessary. By clicking the fourth button, this will be colored magenta, and the three adjacent atoms in the plane (colored orange) will describe a right or left-handed arc.