关于readyState

DOM readyState

• uninitialized 还未开始载入
• loading 载入中
• interactive 已加载
• complete 载入完成

ajax readyState

• 0 (Uninitialized): The object has been created but the open() method hasn’t been called.
• 1 (Loading): The open() method has been called but the request hasn’t been sent.
• 2 (Loaded): The request has been sent.
• 3 (Interactive). A partial response has been received.
• 4 (Complete): All data has been received and the connection has been closed.

function log() {
    try{
        console.log.apply(console, arguments);
    }catch(e) {
        try{
            opera.postError.apply(opera, arguments);
        }catch(e) {
            alert([].join.call(arguments, ''))
        }
    }
}