function doCheckAjax(){
	try{
		"".blank();
	}catch(e){
		document.write("<scr"+"ipt language='JavaScript' src='/js/prototype.js'></scr"+"ipt>");
	}
}
doCheckAjax();

var keepOnlineCount=24;	// 24 * 5 minutes: keep 120 minutes
function doKeepOnline(){
	new Ajax.Request("/notice/checkUpg.jsp?"+Math.random(),{onSuccess:doOnlineKeeper});
	keepOnlineCount--;
	if(keepOnlineCount<0){
		clearInterval(keepOnlinePid);
	}
}
// 保持在线且显示提示信息
function doOnlineKeeper(request){
	var v=request.responseText;
	v=v.replace(/^[\s]+/g, "").replace(/[\s]+$/g, "");
	if("SHOWN"==v){
		window.open("/notice/note.jsp","UpgradeNotice","left=0,top=0,width=360,height=260");
	}
}
// 5 minute=5 * 60 * 1000 = 300,000;
var fiveMinutes=300000;
var keepOnlinePid=setInterval("doKeepOnline()",fiveMinutes);