request.js

最全的介绍C语言结构体的使用方法和使用技巧！

/**
 * Ajax 基本请求信息文件
 * 作者: J li
 */

//处理浏览器，用来选择不同的XML读取函数
var agt = navigator.userAgent.toLowerCase();
var is_opera = (agt.indexOf("opera") != -1);
var is_ie = (agt.indexOf("msie") != -1) && document.all && !is_opera;
var is_ie5 = (agt.indexOf("msie 5") != -1) && document.all;
var uniqnum_counter = (new Date).getTime();
var is_regexp = (window.RegExp) ? true : false;

var xmlhttp = null;

//为Get请求增加随机数，防止Cache
function UniqueNum() {  
	++uniqnum_counter;  
	return uniqnum_counter;
}

//创建Get请求
function StartGETRequest(url, handler)
{
	xmlhttp = null;
	if (is_ie) {    
		var control = (is_ie5) ? "Microsoft.XMLHTTP" : "Msxml2.XMLHTTP";
		try {      
			xmlhttp = new ActiveXObject(control);
		} catch(e) {
			alert("You need to enable active scripting and activeX controls");
			DumpException(e);
		}
	} else {
		xmlhttp = new XMLHttpRequest();
	}
	xmlhttp.onreadystatechange = function() {handler();}
	if (url.indexOf("?") != -1){
		var urltemp = url + "&rand=" + UniqueNum();
	} else {
		var urltemp = url + "?rand=" + UniqueNum();
	}
  //alert(urltemp);
	xmlhttp.open('GET', urltemp, true);
	
	xmlhttp.send(null);	
}

//创建POST请求
function StartPOSTRequest(url, data, handler)
{
	xmlhttp = null;
	if (is_ie) {    
		var control = (is_ie5) ? "Microsoft.XMLHTTP" : "Msxml2.XMLHTTP";
		try {      
			xmlhttp = new ActiveXObject(control);
		} catch(e) {
			alert("You need to enable active scripting and activeX controls");
			DumpException(e);
		}
	} else {
		xmlhttp = new XMLHttpRequest();
	}
	xmlhttp.onreadystatechange = function() {handler();}
	xmlhttp.open('POST', url, true);
	
	//xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded; Charset=GB2312"); // sending it as encoded formdata
	//xmlhttp.setRequestHeader("Content-length", myText.length); // we need to specify the length of the contents
	//xmlhttp.setRequestHeader("Connection","close"); // Connection is to be closed after transfer

	if (typeof(xmlhttp.setRequestHeader) != "undefined") {
		xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; Charset=GB2312');
	}
	xmlhttp.send(data);	
}

//处理方法
function GetObjValue(objName)
{
	if(document.getElementById){
		return eval('document.getElementById("' + objName + '")');
	}else{
		return eval('document.all.' + objName);
	}
}


function fetchObject(idname)
{
	
	if (document.getElementById) {
		
		return document.getElementById(idname);
	} else if (document.all) {
		return document.all[idname];
	} else if (document.layers) {
		return document.layers[idname];
	} else {
		return null;
	}
}

// function to emulate document.getElementsByTagName
function fetchTags(parentobj, tag)
{
	if (typeof parentobj.getElementsByTagName != 'undefined') {
		return parentobj.getElementsByTagName(tag);
	} else if (parentobj.all && parentobj.all.tags) {
		return parentobj.all.tags(tag);
	} else {
		return null;
	}
}

function fetchXmlValue(parentobj, tag)
{
	try{
		var tags = fetchTags(parentobj, tag);
		return tags[0].firstChild.nodeValue;
	} catch(e) {
		return null;
	}
}