var scrollUnitHeight = 150;
var objScroll = null;
 //实现不间断滚动
 function unitScroll()
 {
	 if (objScroll == null || typeof(objScroll.style.top) == "undefined" || objScroll.clientHeight == null)
	 {
		 return;
	 }
 	var top = objScroll.style.top;
 	top = top.replace(/px/ig, "");
	if (typeof(objScroll.clientHeight) == "undefined")
	{
		return;
	}
 objScroll.style.top=(top-1)%(objScroll.clientHeight/2) + "px";
 top = objScroll.style.top.replace(/px/ig, "");
 if (top % scrollUnitHeight == 0)
 {
 		stopScroll();
 		setTimeout('playScroll()', 3000);
 }

 //document.getElementById("debug").innerHTML = news.style.top;
 }
var g_timer1 = -1;
function stopScroll()
{
	if (g_timer1 != -1)
	{
		clearInterval(g_timer1);
		g_timer1 = -1;
	}
}

function playScroll()
{
	stopScroll();
	g_timer1=setInterval('unitScroll()',20) //更改第二个参数可以改变速度，值越小，速度越快。
}