body {text-align: center; padding: 0; margin: 0;}
#container_video {
position: absolute;
width:999px; 
margin-left: -499px; /* moitie de width */
left: 50%;     
height:621px;  
margin-top: -310px;   /* moitie de height */
top: 50%;
background-image:url(http://www.sosve.org/images/prehome/background_spot_tv.gif);
}
p#video_youtube {float:left; margin: 180px 250px; width:400px; height:215px;}
/* hack IE6 */
* html p#video_youtube {float:left; margin: 150px 125px; width:400px; height:215px;}
/* hack IE7 */
*+html p#video_youtube {float:left; margin: 160px 150px; width:400px; height:215px;}