for ( prefix in a ) {
buildParams( prefix, a[ prefix ], traditional, add );
}
}

// Return the resulting serialization
return s.join( "&" ).replace( r20, "+" );
};

jQuery.fn.extend({
serialize: function() {
return jQuery.param( this.serializeArray() );
},
serializeArray: function() {
return this.map(function() {
// Can add propHook for "elements" to filter or add form elements
var elements = jQuery.prop( this, "elements" );
return elements ? jQuery.makeArray( elements ) : this;
})
.filter(function() {
var type = this.type;
// Use .is(":disabled") so that fieldset[disabled] works
return this.name && !jQuery( this ).is( ":disabled" ) &&
rsubmittable.test( this.nodeName ) && !rsubmitterTypes.test( type ) &&
( this.checked || !rcheckableType.test( type ) );
})
.map(function( i, elem ) {
var val = jQuery( this ).val();

return val == null ?
null :
jQuery.isArray( val ) ?
jQuery.map( val, function( val ) {
return { name: elem.name, value: val.replace( rCRLF, "\r\n" ) };
}) :
{ name: elem.name, value: val.replace( rCRLF, "\r\n" ) };
}).get();
}
});


// Create the request object
// (This is still attached to ajaxSettings for backward compatibility)
jQuery.ajaxSettings.xhr = window.ActiveXObject !== undefined ?
// Support: IE6+
function() {

// XHR cannot access local files, always use ActiveX for that case
return !this.isLocal &&

// Support: IE7-8
// oldIE XHR does not support non-RFC2616 methods (#13240)
// See http://msdn.microsoft.com/en-us/library/ie/ms536648(v=vs.85).aspx
// and http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9
// Although this check for six methods instead of eight
// since IE also does not support "trace" and "connect"
/^(get|post|head|put|delete|options)$/i.test( this.type ) &&

createStandardXHR() || createActiveXHR();
} :
// For all other browsers, use the standard XMLHttpRequest object
createStandardXHR;

var xhrId = 0,
xhrCallbacks = {},
xhrSupported = jQuery.ajaxSettings.xhr();

// Support: IE<10
// Open requests must be manually aborted on unload (#5280)
// See https://support.microsoft.com/kb/2856746 for more info
if ( window.attachEvent ) {
window.attachEvent( "onunload", function() {
for ( var key in xhrCallbacks ) {
xhrCallbacks[ key ]( undefined, true );
}
});
}

// Determine support properties
support.cors = !!xhrSupported && ( "withCredentials" in xhrSupported );
xhrSupported = support.ajax = !!xhrSupported;

// Create transport if the browser can provide an xhr
if ( xhrSupported ) {

jQuery.ajaxTransport(function( options ) {
// Cross domain only allowed if supported through XMLHttpRequest
if ( !options.crossDomain || support.cors ) {

var callback;

return {
send: function( headers, complete ) {
var i,
xhr = options.xhr(),
id = ++xhrId;

// Open the socket
xhr.open( options.type, options.url, options.async, options.username, options.password );

// Apply custom fields if provided
if ( options.xhrFields ) {
for ( i in options.xhrFields ) {
xhr[ i ] = options.xhrFields[ i ];
}
}

// Override mime type if needed
if ( options.mimeType && xhr.overrideMimeType ) {
xhr.overrideMimeType( options.mimeType );
}

// X-Requested-With header
// For cross-domain requests, seeing as conditions for a preflight are
// akin to a jigsaw puzzle, we simply never set it to be sure.
// (it can always be set on a per-request basis or even using ajaxSetup)
// For same-domain requests, won't change header if already provided.
if ( !options.crossDomain && !headers["X-Requested-With"] ) {
headers["X-Requested-With"] = "XMLHttpRequest";
}

// Set headers
for ( i in headers ) {
// Support: IE<9
// IE's ActiveXObject throws a 'Type Mismatch' exception when setting
// request header to a null-value.
//
// To keep consistent with other XHR implementations, cast the value
// to string and ignore `undefined`.
if ( headers[ i ] !== undefined ) {
xhr.setRequestHeader( i, headers[ i ] + "" );
}
}

// Do send the request
// This may raise an exception which is actually
// handled in jQuery.ajax (so no try/catch here)
xhr.send( ( options.hasContent && options.data ) || null );

// Listener
callback = function( _, isAbort ) {
var status, statusText, responses;

// Was never called and is aborted or complete
if ( callback && ( isAbort || xhr.readyState === 4 ) ) {
// Clean up
delete xhrCallbacks[ id ];
callback = undefined;
xhr.onreadystatechange = jQuery.noop;

// Abort manually if needed
if ( isAbort ) {
if ( xhr.readyState !== 4 ) {
xhr.abort();
}
} else {
responses = {};
status = xhr.status;

// Support: IE<10
// Accessing binary-data responseText throws an exception
// (#11426)
if ( typeof xhr.responseText === "string" ) {
responses.text = xhr.responseText;
}

// Firefox throws an exception when accessing
// statusText for faulty cross-domain requests
try {
statusText = xhr.statusText;
} catch( e ) {
// We normalize with Webkit giving an empty statusText
statusText = "";
}

// Filter status for non standard behaviors

// If the request is local and we have data: assume a success
// (success with no data won't get notified, that's the best we
// can do given current implementations)
if ( !status && options.isLocal && !options.crossDomain ) {
status = responses.text ? 200 : 404;
// IE - #1450: sometimes returns 1223 when it should be 204
} else if ( status === 1223 ) {
status = 204;
}