function _printDateTimeStr(){
	var oNow = new Date();
	var s = oNow.getFullYear() + '-' + (oNow.getMonth() + 1) + "-" + oNow.getDate() + " " + oNow.toLocaleTimeString();
	if (bObj){
		bObj.innerHTML = s;
	}else{
		document.writeln(s);
	}
}

function printTimeTick(){
	window.setInterval("_printDateTimeStr();", 1000);
}

var bObj = document.getElementById("datetimeTick");
printTimeTick();