var request = false;
try {
 request = new XMLHttpRequest();
} catch (trymicrosoft) {
 try {
   request = new ActiveXObject("Msxml2.XMLHTTP");
 } catch (othermicrosoft) {
   try {
	 request = new ActiveXObject("Microsoft.XMLHTTP");
   } catch (failed) {
	 request = false;
   }  
 }
}

if (!request)
 alert("Error initializing XMLHttpRequest!");


//======
function RefreshCity(id) {
	var url = "/inc/read_weather.php?id="+id;
	request.open("GET", url, true);
	request.onreadystatechange = RefreshCity_block;
	request.send(null);
}
function RefreshCity_block() {
	if (request.readyState == 4)
		if (request.status == 200)
			document.getElementById("weather_block").innerHTML = request.responseText;
		else
			if (request.status == 404) alert("Request URL does not exist");
				else alert("Error: status code is " + request.status);
}
//=======