30. The medium of claim 29 further comprising one or more instructions for: providing a first scrolling bar for scrolling the input description; and providing a second scrolling bar for scrolling the output description.
31. The medium of claim 30 wherein in response to controlling one of the first scrolling bar or the second scrolling bar, the other scrolling bar is automatically controlled in proportion to a controlled amount in said one of the first scrolling bar and the second scrolling bar.