使用prototype实时获取数据

<script>
  
//每隔30分钟去服务器取事件趋势信息
var eventTrendInterval =setInterval("pushEventTrend()",1800000);

//使用异步方式去服务器，获取事件趋势信息
function pushEventTrend()
{
  	var url = "*.action";

  	new Ajax.Updater(
  	{success: 'eventTrendDiv'},
  	url,
    {
      method:'post',
      onFailure: reportError
    });
}



function reportError(request)
{
	$("eventTrendDiv").innerHTML = "发生错误";
}

</script>