if (document.images) {
//イメージのpreload
  imgfile = new Array();
  imgfile[0]=new Image(); imgfile[0].src="img/dance/motion1.jpg";
  imgfile[1]=new Image(); imgfile[1].src="img/dance/motion2.jpg";
  imgfile[2]=new Image(); imgfile[2].src="img/dance/motion3.jpg";
  imgfile[3]=new Image(); imgfile[3].src="img/dance/motion4.jpg";
  imgfile[4]=new Image(); imgfile[4].src="img/dance/motion5.jpg";
  imgfile[5]=new Image(); imgfile[5].src="img/dance/motion6.jpg";
  imgfile[6]=new Image(); imgfile[6].src="img/dance/motion7.jpg";
  imgfile[7]=new Image(); imgfile[7].src="img/dance/motion8.jpg";
}
//スライドショー
timerID = 0;
indx = 0;
function nextSlide() {
  if (document.images) {
    if (timerID > 0) {
       clearTimeout(timerID);
    }
    document.slideimg.src = imgfile[indx].src;
    indx++;
    if (indx < imgfile.length) {
        timerID = setTimeout("nextSlide()",500); //1秒毎に表示切り換え
    }
  }
}
function startSlide() {
    indx = 0;
    nextSlide();
}