最新的$.ajax 
async Boolean Default: true
By default, all requests are sent asynchronous (e.g. this is set to true by default). If you need synchronous requests, set this option to false. Note that synchronous requests may temporarily lock the browser, disabling any actions while the request is active.
beforeSend Function
A pre-callback to modify the XMLHttpRequest object before it is sent. Use this to set custom headers etc. The XMLHttpRequest is passed as the only argument. This is an Ajax Event. You may return true in function to cancel the request.
function (XMLHttpRequest) {
this; // the options for this ajax request
}
Pages: [1] [2]
By default, all requests are sent asynchronous (e.g. this is set to true by default). If you need synchronous requests, set this option to false. Note that synchronous requests may temporarily lock the browser, disabling any actions while the request is active.
beforeSend Function
A pre-callback to modify the XMLHttpRequest object before it is sent. Use this to set custom headers etc. The XMLHttpRequest is passed as the only argument. This is an Ajax Event. You may return true in function to cancel the request.
function (XMLHttpRequest) {
this; // the options for this ajax request
}
Pages: [1] [2]
那只有买书支持了!
NetBeans IDE Early Access for PHP的问题
Only for requests with 'jsonp' or 'script' dataType and GET type. Forces the request to be interpreted as a certain charset. Only needed for charset differences between the remote and local content.
看来只有这两个了