function scrollDiv(id, time, step) {
var obj = document.getElementById(id);
if (!obj) {
  alert("id´íÎó");
  return;
}

var len=obj.childNodes.length;
var obj1=null;
var obj2=null;
var idx=0;
while(!obj1||!obj1.tagName){
  obj1=obj.childNodes[idx++];
}
while(!obj2||!obj2.tagName){
  obj2=obj.childNodes[idx++];
}

obj2.innerHTML = obj1.innerHTML;
//obj.scrollTop+=30
function scro() {
  if(obj.val){
	obj.val=null;
  }
  var topval=obj2.offsetTop;
  if(obj2.offsetTop >obj.offsetTop){
	topval=topval-obj.offsetTop;
  }
  if(topval-obj.scrollTop<=0){
	obj.scrollTop-=obj1.offsetHeight ;
  }else{ 
	obj.scrollTop+=step; 
  }
}


obj.inter = setInterval(scro, time)
obj.onmouseover = function() {
  clearInterval(obj.inter);
}
obj.onmouseout = function() {
  obj.inter = setInterval(scro, time);
}
}
function test(){
scrollDiv("gg_content", 200, 1);
}