Ajax的关键在于XMLHttpRequest对象，理解这个对象的例子如下：@H_403_2@
<!DOCTYPE HTML>@H_403_2@
<html>@H_403_2@
<head>@H_403_2@
<title>Ajax</title>@H_403_2@
</head>@H_403_2@
<body>@H_403_2@
<div>@H_403_2@
<button>Apple</button>@H_403_2@
<button>Samsung</button>@H_403_2@
<button>IBM</button>@H_403_2@
</div>@H_403_2@
<div id="target">@H_403_2@
Press a button@H_403_2@
</div>@H_403_2@
<script>@H_403_2@
var buttons = document.getElementsByTagName("button");@H_403_2@
for(var i = 0; i < buttons.length; i++){@H_403_2@
buttons[i].onclick = handleButtonPress;@H_403_2@
}@H_403_2@
@H_403_2@function handleButtonPress(e){@H_403_2@
var httpRequest = new XMLHttpRequest();@H_403_2@
httpRequest.onreadystatechange = handleResponse;@H_403_2@
httpRequest.open("GET",e.target.innerHTML + ".html");@H_403_2@
httpRequest.send();@H_403_2@
}@H_403_2@
function handleResponse(e){@H_403_2@
if(e.target.readyState == XMLHttpRequest.DONE &&@H_403_2@
e.target.status == 200){@H_403_2@
document.getElementById("target").innerHTML@H_403_2@
= e.target.responseText;@H_403_2@
}@H_403_2@
}@H_403_2@
</script>@H_403_2@
</body>@H_403_2@
</html>@H_403_2@
