var downLayerId;
var dropDegree = 2;
var doDirect;
var DirectTerm = 3500;
var curDropIdx = 0;
var objlist = document.getElementById("DropHit").getElementsByTagName("div");
var len = objlist.length;

function DirectDown()
{
    clearInterval(doDirect);
    clearInterval(downLayerId);
    
    for(i = curDropIdx ;i < len + curDropIdx;i++)
    {
        objlist[i%len].style.top = parseInt(objlist[i%len].style.height) * (-1*((i-curDropIdx)%len)) + "px";
    }
    
    var temp = 'setInterval("DownLayer()",13)';
    downLayerId = eval(temp);
}

function DownLayer()
{
    if(parseInt(objlist[curDropIdx].style.top) < parseInt(objlist[curDropIdx].style.height))
    {
        for(j = curDropIdx ;j < len + curDropIdx;j++)
        {
            objlist[j%len].style.top = parseInt(objlist[j%len].style.top) + dropDegree + "px";
        }
    }
    else
    {
        clearInterval(downLayerId);
        
        for(j = curDropIdx ;j < len + curDropIdx;j++)
        {
            objlist[j%len].style.top = parseInt(objlist[j%len].style.height) *((-1*((j-curDropIdx)%len))+1) + "px";
        }
        curDropIdx = (curDropIdx + 1) ;
        curDropIdx = curDropIdx > len-1 ? curDropIdx%len:curDropIdx;
        var temp = 'setInterval("DirectDown()",DirectTerm)';
        doDirect = eval(temp);
    }
}

function rolling(s) {
    clearInterval(doDirect);
    clearInterval(downLayerId);
	if(s==1) {
    	var temp = 'setInterval("DownLayer()",13)';
    	downLayerId = eval(temp);
	}
}

DirectDown();