Click the bracket (the first square on the right side of the handwriting input) to insert a space. Click the thick arrow with an X to delete the last character you wrote. Click the skinnier arrow to insert a line break (the equivalent to pressing ↵ Enter). Click the rectangle with a smaller rectangle inside (near the top-right corner of the handwriting panel) to undock the panel. This allows you to move it around the screen. Click the X at the top-right corner of the panel to close it.
