Good puzzle: connect the six boxes without crossing any lines

Draw a line connecting the two boxes labeled 1. Draw another line connnecting the boxes labeled 2. Draw a third line connecting the boxes labeled 3. The lines can't intersect. The lines can't go beyond the bounds of the rectangle enclosing them. [ADD: The lines don't have to be straight.] There's nothing tricky or disappointing about the solution. (Here's the solution.)