This trick needs to be performed while standing behind a taable with the spectators at a little distance away. There are three glasses all the same size on the table. The magician stacks the glasses one on top of the other. He then takes three differently colored liquids such as Orange Drink, Cola, and Lemonade.
 
The magician then proceeds to pour one of the liquids, for example Orange Drink, into any one of the glasses selected by a spectator without rearranging any of the glasses. This can be done even if the middle or bottom glass is selected first! Another glass can be selected by the spectator and the next colored liquid, for example Cola, poured into it even if it is below the first glass! The remaining glass is then filled with the third colored liquid.
 
AMAZING? YES! IMPOSSIBLE? NOT AT ALL, when you know how.