<SCRIPT language="JavaScript">
<!--
// 時間ごとに背景画像を変更
h = (new Date()).getHours();
if((h >= 0) && (h < 6)) document.body.style.backgroundImage = "url(bg1.gif)";
if((h >= 6) && (h < 12)) document.body.style.backgroundImage = "url(bg2.gif)";
if((h >= 12) && (h < 18)) document.body.style.backgroundImage = "url(bg3.gif)";
if((h >= 18) && (h < 24)) document.body.style.backgroundImage = "url(bg4.gif)";
//-->
</SCRIPT>