var dropDegree = 1; //步进像素，速度
var divWidth = 132; //单个元素的宽度
var DirectTerm = 20;//循环时间间隔
var objlist = document.getElementById("DropHit").getElementsByTagName("div");
var len = objlist.length;

function MovieDiv() 
{
    for (i = 0; i < len; i++) 
    {
        objlist[i].style.left = (parseInt(objlist[i].style.left) - dropDegree) + "px";

        if (parseInt(objlist[i].style.left) < (0 - divWidth)) 
        {
            objlist[i].style.left = (parseInt(objlist[i].style.left) + divWidth * len - dropDegree) + "px";
        }
    }
}

var temp = 'setInterval("MovieDiv()",' + DirectTerm + ')';
downLayerId = eval(temp);

function rolling(s) 
{
    clearInterval(downLayerId);
    if (s == 1) 
	{
	    var temp = 'setInterval("MovieDiv()",' + DirectTerm + ')';
    	downLayerId = eval(temp);
	}
}