// JavaScript Document
/*
xmlHttpRequest 操作
 
*/

var xmlHttp=false;
var showArea="";
var loadNumber=0;
var getFileName="";
var startTag=true;
//启动加载 
var loadArray=new Array("");
var areaArray=new Array("");

function createXmlhttp(){
	if(window.XMLHttpRequest){
		xmlHttp = new XMLHttpRequest();
		if (xmlHttp.overrideMimeType){
			xmlHttp.overrideMimeType("text/xml");
		}

	}
	else if(window.ActiveXObject){
		try{
			xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
		}catch(e){
			xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
		}
	}
	if(!xmlHttp){
		window.alert("Your broswer not support XMLHttpRequest!");
	}
	return xmlHttp;
}


//启动加载
function startLoad(){
	//alert('start');
	if (loadNumber<loadArray.length){
		showArea=areaArray[loadNumber];
		getFileName=loadArray[loadNumber];
		getFile(loadArray[loadNumber]);
	}else{
		startTag=false;
	}
}


function reGet(){
	createXmlhttp();
	
	try{
		xmlHttp.onreadystatechange = setShowArea;
		//xmlHttp.setRequestHeader("Cache-Control","no-cache"); 
		xmlHttp.open("GET", getFileName, true);
		xmlHttp.setRequestHeader("If-Modified-Since","0");
		xmlHttp.setRequestHeader("Cache-Control","no-cache"); 
		//xmlHttp.setRequestHeader("charset","gb2312");
		xmlHttp.send(null);	
	}catch(exception){
		alert("no file!");
	}
}
function getFile(fileName){
	if(startTag){
		loadNumber=loadNumber+1;
	}
	createXmlhttp();
	
	try{
		xmlHttp.onreadystatechange = setShowArea;
		//xmlHttp.setRequestHeader("Cache-Control","no-cache"); 
		xmlHttp.open("GET", fileName, true);
		//xmlHttp.setRequestHeader("If-Modified-Since","0");
		xmlHttp.setRequestHeader("Cache-Control","no-cache"); 
		//xmlHttp.setRequestHeader("charset","gb2312");
		xmlHttp.send(null);	
	}catch(exception){
		alert("no file!");
	}
}

function setShowArea (){
	if(xmlHttp.readyState == 4){
		//alert(xmlHttp.status);
		if (xmlHttp.status == 200 || xmlHttp.status == 0){
			document.getElementById(showArea).innerHTML=xmlHttp.responseText;
			if (startTag){
				startLoad();
				
			}
		}
		//if (xmlHttp.status== 400){
			//reGet();
		//}
	}else{
		document.getElementById(showArea).innerHTML="loading...";
	}	
}

function setContent(fileName){
	showArea="contentArea"
	getFile(fileName)
}