XMLHttpRequest提供了一种简单的方式在不刷新页面的同时从URL中检索数据。网页可以只更新页面部分的内容。

function loadXMLDoc() {
    if (window.XMLHttpRequest) {// code for IE7+,Firefox,Chrome,Opera,Safari
        xmlhttp = new XMLHttpRequest();
    }
    else {// code for IE6,IE5
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    
    xmlhttp.onreadystatechange = function () {
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
            var item = xmlhttp.responseXML;
            var User = item.getElementsByTagName("User")[0].attributes['0'].value;
            var Pwd = item.getElementsByTagName("Pwd")[0].attributes['0'].value;
            document.getElementById("myDiv").innerHTML = User + "\r" + Pwd;
        }
    }
    xmlhttp.open("GET","..\\Db\\xmlhttp_info.xml",true);
    xmlhttp.send();
}

XML

<root>
  <User value="Edward">
    Edward
  </User>
  <Pwd value="123">
    123
  </Pwd>
</root>

Reference:

XMLHttpRequest

AJAXDatabase Example

XMLDOM Get Node Values