what is AJAX exactly?

• who is Ajax?

特洛伊(Troy)看过没？阿伽门侬(Agamemnon)手下除了阿基里斯（Achilles, 战神，敏捷型英雄）的排行老二的那个大个（ajax,使锤的，力量型的哈）。就是那后来被赫克托(Hektor,大王子)杀了（秒杀）的那个。

• what is Ajax?

XMLHttpRequest + Javascript

• what is XMLHttpRequest ?

look at this:

function new_XMLHttpRequest() {
    var xmlreq = false;
    if (window.XMLHttpRequest) {
        xmlreq = new XMLHttpRequest();
    } 
    else if (window.ActiveXObject) {
            // Try ActiveX
        try { 
            xmlreq = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e1) { 
            // first method failed 
            try {
                xmlreq = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e2) {
                 // both methods failed 
                 xmlreq = false;
            } 
        }
     }
     return xmlreq;
}

• what is Javascript

em… http://en.wikipedia.org/wiki/Javascript

我说: ajax 因为 XMLHttpRequest 而强大.