camNo = 1;
function switchCam() {
	switch(camNo) {
	case 0:
		document.liveCam.src = "http://horilab.ia.inf.shizuoka.ac.jp/livecamera/horilab_cam.jpg";
		camNo = 1;
		break;
	case 1:
		document.liveCam.src = "http://horilab.ia.inf.shizuoka.ac.jp/livecamera/webcam.jpg";
		camNo = 2;
		break;
	case 2:
		document.liveCam.src = "http://horilab.jp/photo/3cam.jpg";
		camNo = 0;
		break;
	}
}