Iframe shortcode Issue

The iframe resizes but the video is not correct by centering. Look at the video.

[iframe src="http://www.panorama.airpics.org/tour_hafenresidenz/index.html" width="960px" height="400px"]

However if we remove the height and set the width to 100% it does but the height is not correct.

[iframe src="http://www.panorama.airpics.org/tour_hafenresidenz/index.html" width="100%"]

But if we set the height to 100% and add a div around the iframe with a height of 400px it seems to work and keep the room better in focus.

<div style="height:400px;"> <iframe width="100%" frameborder="0" seamless="seamless" style="width:100%;height:100%;" src="http://www.panorama.airpics.org/tour_hafenresidenz/index.html"> </iframe> </div>