背景向下滑落

請copy下面0既語法啦!!!

<script language="JavaScript"> <!-- Begin var backgroundOffset = 0; var bgObject = eval('document.body'); function scrollBG(maxSize) { backgroundOffset = backgroundOffset + 1; if (backgroundOffset > maxSize) backgroundOffset = 0; bgObject.style.backgroundPosition = "0 " + backgroundOffset; } var ScrollTimer = window.setInterval("scrollBG(307)", 64); // End --> </script>