function InitAjax()
{
　var ajax=false; 
　try { 
　　ajax = new ActiveXObject("Msxml2.ServerXMLHTTP"); 
　} catch (e) { 
　　try { 
　　　ajax = new ActiveXObject("Microsoft.XMLHTTP"); 
　　} catch (E) { 
　　　ajax = false; 
　　} 
　}
　if (!ajax && typeof XMLHttpRequest!='undefined') { 
　　ajax = new XMLHttpRequest(); 
　} 
　return ajax;
}

function ClearOption(ListObj) {
	var i;
	for ( i = ListObj.length - 1; i >= 0; i-- ) {
		ListObj.options[i] = null;
	}
}

function GetGameArea(game_name, area_name, server_name)
{	
	
	var hr = InitAjax();
	if (!hr) {
		alert("您的浏览器不支持本网页的功能，请您升级浏览器！");
		return false;
	}
	var game_list, area_list, server_list;
	game_list = document.getElementById(game_name);
	area_list = document.getElementById(area_name);
	server_list = document.getElementById(server_name);
	hr.onreadystatechange = function(){
		if ((hr.readyState != 4) || (hr.status != 200)) 
			return false;
		ClearOption(area_list);
		ClearOption(server_list);
		var oa, i, info;
		oa = hr.responseText.split("$;$");
		area_list.options[0] = new Option('请选择..', '');
		for (i=0; i<oa.length; i++){
			info = oa[i].split("$,$");
			area_list.options[i+1] = new Option(info[1], info[0]);
		}
		if (area_list.options.length>0) {
			area_list.options[0].selected = true;
			GetGameServer(game_name, area_name, server_name)
		}
	}
	var areaurl = "GAS.asp?gid=" + game_list.value;
	hr.open("GET", areaurl, false);
	hr.send(null); 
}

function GetGameServer(game_name, area_name, server_name)
{   
	var hr = InitAjax();
	if (!hr) {
		alert("您的浏览器不支持本网页的功能，请您升级浏览器！");
		return false;
	}
	var game_list, area_list, server_list;
	game_list = document.getElementById(game_name);
	area_list = document.getElementById(area_name);
	server_list = document.getElementById(server_name);
 
	hr.onreadystatechange = function(){
		if ((hr.readyState != 4) || (hr.status != 200)) 
			return false;
		ClearOption(server_list);
		var oa, i, info;
		oa = hr.responseText.split("$;$");
		server_list.options[0] = new Option('请选择..', '');
		for (i=0; i<oa.length; i++){
			info = oa[i].split("$,$");
			server_list.options[i+1] = new Option(info[1], info[0]);
		}
		if (server_list.options.length>0)
			server_list.options[0].selected = true;
	}
	var areaurl = "GAS.asp?gid=" + game_list.value + "&aid=" + area_list.value;
	hr.open("GET", areaurl, false);
	hr.send(null); 
}