Punch Bowl

This puzzle may not seem similar, at first. But the solution is similar. You are next to the punch bowl, at a party. You happen to have two glasses, one holds five units (cups, cubic centimeters, whatever), and the other holds three units. You must get exactly four units of punch (doctor's orders perhaps), by filling glasses (must be all the way) and dumping back into the bowl. How can you do that? The answer is also below. Note: our aim is to have four units in the five unit glass. Every time you fill, transfer, or dump water it counts as one move. The goal is to do it in as little moves as possible.