Adjust the width of your browser so that both I-beam icons align with the edges of the webtv image. The left one should align by default; adjust your window so that the right one aligns the same way.
Adjust the height of your browser so that the only part of this page that you see is the webtv image. Note: it's OK to leave a little margin below the image, but don't go any further than the centerline of the I-beam icons.
Also, make sure automatic image loading is on - webtv doesn't give you a choice. You are also not allowed to use the horizontal scroll bar when simulating webtv - it doesn't have one.