function init() {
    video = document.getElementById("video");
    webm = document.getElementById("webm");
}
var videos = new Array();

videos[0] = [
	     "video/kungfu.mp4",
	     "video/kungfu.webm"
	     ];
videos[1] = [
    	     "video/rio.mp4",
    	     "video/rio.webm"
	     ];
videos[2] = [
    	     "video/releone.mp4",
    	     "video/releone.webm"
    	    ];

function switchVideo(n) {
	
    var mp4 = document.getElementById("mp4");
    var webm = document.getElementById("webm");

    mp4.setAttribute("src", videos[n][0]);
    webm.setAttribute("src", videos[n][1]);

    video.load();
}