How do I format a cell so that it will display a symbol such as: green arrow
up, red arrow down, or black horizontal arrow? This would be used to show
the rise, fall, or steadiness of day-to-day stock prices, as follows: 1) if
d13f13, then green arrow up, 2) if d13<f13, then red arrow down, or 3) if
d13=f13, then black horizontal arrow.