var counterPop = 1;
 function openWindow() {
    var options = "width=" + 600 + ",height=" + 400 + ",";
    options += "resizable=yes,scrollbars=yes,status=yes,";
    options += "menubar=yes,toolbar=yes,location=yes,directories=no";
    var newWin = window.open('http://atech.com.vn', 'newWin', options);
    newWin.focus();
  }
 function popUpWithTimeSpecified()
 {
 if(counterPop == 1)
	{
    var dTime = new Date();
    var hours = dTime.getHours();
	if((hours >= 18 && hours <= 24) || (hours >= 0 && hours <= 6))
		openWindow();
	// document.write(hours);
	counterPop++;
    }
 }