4. The system of claim 3 wherein the pattern comprises lines visible on the display screen, each line within an expandable container image of a similar type and spaced from the other lines within that expandable container image.
4. The system of claim 3 wherein the pattern comprises lines visible on the display screen, each line within an expandable container image of a similar type and spaced from the other lines within that expandable container image. 5. The system of claim 4 wherein the lines within at least one expandable container image are solid and the lines within another expandable container image are dashed.