建立一個簡單的AJAX系統

function login()

{

url= "auth_ajax.php?id="+document.getElementById("name").value+"&pwd="+

document.getElementById("pwd").value;

try

{ xhr=new XMLHttpRequest(); //建立一個AJAX物件

if (xhr.overrideMimeType) xhr.overrideMimeType('text/xml');}

catch (e) { try

{ xhr=new ActiveXObject("Msxml2.XMLHTTP"); }//如果標準的建不起來，用IE的方法建立

catch (ee)

{ alert("Your Browser doesn't support XMLHttpRequest"); return false; }}

xhr.onreadystatechange = function()

{

if (xhr.readyState==4 && xhr.status==200) //如果呼叫成功，處理底下

{ alert(xhr.responseText);}

}

xhr.open("get",url,true);

xhr.setRequestHeader('Content-Type','application/x-www-urlencoded; charset=utf-8');

xhr.send(null);

}