function Inint_AJAX() {
	try { return new ActiveXObject("Msxml2.XMLHTTP"); } catch(e) {} //IE
	try { return new ActiveXObject("Microsoft.XMLHTTP"); } catch(e) {} //IE
	try { return new XMLHttpRequest(); } catch(e) {} //Native Javascript
	alert("XMLHttpRequest not supported");
	return null;
};

function getCityByCountryId(id, mt_url, city_id) {
	var req = Inint_AJAX();
	req.onreadystatechange = function () {
		if (req.readyState==4) {
			if (req.status==200) {
				var regText = req.responseText;
				document.getElementById('metro_pop').innerHTML=regText; //return value
				if (regText=='') document.getElementById('chooseMetro').innerHTML="нет";
				else document.getElementById('chooseMetro').innerHTML='<a onclick="return metro_up()" href="#">выбрать</a>';
			}
		}
	};
	req.open("GET", "/ajax/get_metro.php?country_id="+id+mt_url+'&city_id='+city_id);
	req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded;charset=utf-8"); // set Header
	req.send(null);
	return false;
}