一，XMLHttpRequest很少的几个 方法和属性。
·open()：建立到服务器的新请求。
·send()：向服务器发送请求。
·abort()：退出当前请求。
·readyState：提供当前 HTML 的就绪状态。
·responseText：服务器返回的请求响应文本。
<script language="javascript" type="text/javascript">
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!");
</script>
二 将 XMLHttpRequest 创建代码移动到方法中
<script language="javascript" type="text/javascript">
var request;
function createRequest() {
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!");
}
</script>
三，使用 XMLHttpRequest 的创建方法
<script language="javascript" type="text/javascript">
var request;
function createRequest() {
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 getCustomerInfo() {
createRequest();
// Do something with the request variable
}
</script>