var x = 50,y = 60
	var xin = true, yin = true
	var step = 1
	var delay = 1
	var obj=document.getElementById("index_drift")
	function floatAD() {
		var L=T=0
		var R= document.body.clientWidth-obj.offsetWidth
		var B = document.body.clientHeight-obj.offsetHeight
		obj.style.left = x + document.body.scrollLeft
		obj.style.top = y + document.body.scrollTop
		x = x + step*(xin?1:-1)
		if (x < L) { xin = true; x = L}
		if (x > R){ xin = false; x = R}
		y = y + step*(yin?1:-1)
		if (y < T) { yin = true; y = T }
		if (y > B) { yin = false; y = B }
	}
	var itl= setInterval("floatAD()", delay)
	obj.onmouseover=function(){clearInterval(itl)}
	obj.onmouseout=function(){itl=setInterval("floatAD()", delay)}