简单ajax应用，个人参考笔记
案例一：
ajax.html
<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Insert title here</title><script language="javascript" src="ajax.js"></script></head><body><input type="text" name="myname" onmouseout="process()"/><input type="button" value="submit" onclick="process()" /><div id="message"></div></body></html>
var xmlHttp;xmlHttp = create_obj();function create_obj() {var xmlHttp=null;try {// Firefox, Opera 8.0+, SafarixmlHttp = new XMLHttpRequest();} catch (e) {// Internet Explorertry {xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");} catch (e) {xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");}}return xmlHttp;}function process() {name = document.getElementsByName("myname")[0].value;xmlHttp.open("GET", "ajax.php?name=" + name, true);xmlHttp.onreadystatechange = handle_f;xmlHttp.send(null);}function handle_f() {if (xmlHttp.readyState == 4) {if (xmlHttp.status == 200) {result = xmlHttp.responseText;c = document.getElementById("message");c.innerHTML = result;}else {alert(xmlHttp.statusText);}} }<?php$user=array("111","222","333","444","555");if (in_array($_GET["name"],$user)) {echo $_GET["name"]." exist.";}else {echo $_GET["name"]." not exist.";}<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Insert title here</title><script language="javascript" src="ajax_xml.js"></script></head><body><select id="s_c" multiple="multiple" size="12" style="width: 160px;"><option value="111">111</option><option value="222">222</option><option value="333">333</option><option value="444">444</option><option value="555">555</option><option value="666">666</option><option value="777">777</option><option value="888">888</option><option value="999">999</option><option value="1010">1010</option><option value="1111">1111</option><option value="1212">1212</option><option value="1313">1313</option><option value="1414">1414</option></select></br><input type="button" value="RandSelect" onclick="randSelect(1,10,3)" /><input type="button" value="select" onclick="process()" /><input type="button" value="refresh" onclick="refresh()" /><div id="result"></div><p>
var xmlHttp;xmlHttp = create_obj();function create_obj() {var xmlHttp = null;try {// Firefox, Opera 8.0+, SafarixmlHttp = new XMLHttpRequest();} catch (e) {// Internet Explorertry {xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");} catch (e) {xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");}}return xmlHttp;}function createxmlcon() {var xml = "<members>";var options = document.getElementById("s_c").childNodes;var option = null;for ( var i = 0; i < options.length; i++) {option = options[i];if (option.selected) {xml = xml + "<member>" + option.value + "<\/member>";}}xml += "<\/members>";return xml;}function process() {var date = new Date();temp = date.getTime();var url = "ajax_xml.php?timestamp=" + temp;xmlcon = createxmlcon();xmlHttp.open("POST", url, true);xmlHttp.setRequestHeader("Content-type","application/x-www-form-urlencoded");xmlHttp.setRequestHeader("Content-length", xmlcon.length);xmlHttp.onreadystatechange = handle_f;xmlHttp.send(xmlcon);}function handle_f() {if (xmlHttp.readyState == 4) {if (xmlHttp.status == 200) {parseResult();} else {alert(xmlHttp.statusText);}}}function parseResult() {var obj = document.getElementById("result");if (obj.hasChildNodes()) {obj.removeChild(obj.childNodes[0]);}text = xmlHttp.responseText;var obj_text = document.createTextNode(text);obj.appendChild(obj_text);}function refresh() {var options = document.getElementById("s_c");var option = "";for ( var i = 0; i < options.length; i++) {option = options[i];if (option.selected) {option.selected = false;}}}function randSelect(start, end, num) {var options = document.getElementById("s_c");var arr = new Array();if (start >= 0 && end >= start) {for ( var i = start, j = 0; i <= end; i++, j++) {arr[j] = i;if (options.selectedIndex >= 0) {options[i].selected = false;}}}if (num > arr.length || num < 0) {return false;} else {for ( var k = 0; k < num; k++) {var indexN = Math.floor(Math.random() * arr.length);for ( var i = 0; i < arr.length; i++) {if (i == indexN) {options[i].selected = true;}}}}// var options = document.getElementById("s_c");// randnum=Math.floor(Math.random()*10+1);// options[randnum].selected=true;}<?phpheader("Content-Type:text/html; charset=UTF-8");$fp=fopen("php://input", "r+");$data="";while (!feof($fp)) {$data.=fread($fp, 4096);}fclose($fp);$doc=new DOMDocument();$doc->loadXML($data);$root=$doc->getElementsByTagName("members");$root=$root->item(0);$userid=$root->getElementsByTagName("member");foreach ($userid as $rootdata) {echo $rootdata->nodeValue;echo " ";}