用document.onreadystatechange的方法来监听页面状态改变

用document.onreadystatechange的方法来监听状态改变，
然后用document.readyState == “complete”判断是否加载完成
代码如下：
document.onreadystatechange = subSomething;//当页面加载状态改变的时候执行这个方法.
function subSomething(){
    if(document.readyState == “complete”) //当页面加载状态
    myform.submit(); //表单提交
}

页面加载readyState的五种状态：
0: (Uninitialized) the send( ) method has not yet been invoked.

  （未初始化）还没有调用send()方法
1: (Loading) the send( ) method has been invoked, request in progress.

  （载入）已调用send()方法，正在发送请求
2: (Loaded) the send( ) method has completed, entire response received.

  （载入完成）send()方法执行完成，已经接收到全部响应内容
3: (Interactive) the response is being parsed.

  （交互）正在解析响应内容
4: (Completed) the response has been parsed, is ready for harvesting.

  （完成）响应内容解析完成，可以在客户端调用了