Renamed $.ajax's "before"-option to "beforeSend" to prevent conflict with form plugin - may be a good convention to use beforeXXX and afterXXX everytime for callbacks...

build/test/data/name.php

@@ -19,7 +19,7 @@ if($name == 'foo') {
 	die();
 }
 $request = apache_request_headers();
-$request = $request['customHeader'];
+$request = $request['X-Custom-Header'];
 if(strlen($request) > 0) {
 	echo $request;
 	die();

src/ajax/ajax.js

@@ -484,7 +484,7 @@ jQuery.extend({
 	 * (Boolean) async - By default, all requests are send asynchronous (set to true).
 	 * If you need synchronous requests, set this option to false.
 	 *
-	 * (Function) before - A pre-callback to set custom headers etc., the
+	 * (Function) beforeSend - A pre-callback to set custom headers etc., the
 	 * XMLHttpRequest is passed as the only argument.
 	 *
 	 * @example $.ajax({
@@ -525,7 +525,7 @@ jQuery.extend({
 			contentType: "application/x-www-form-urlencoded",
 			processData: true,
 			async: true,
-			before: null
+			beforeSend: null
 		}, s);
 
 		// if data available
@@ -568,8 +568,8 @@ jQuery.extend({
 			xml.setRequestHeader("Connection", "close");
 			
 		// Allow custom headers/mimetypes
-		if( s.before )
-			s.before(xml);
+		if( s.beforeSend )
+			s.beforeSend(xml);
 
 		// Wait for a response to come back
 		var onreadystatechange = function(isTimeout){

src/ajax/ajaxTest.js

@@ -282,12 +282,12 @@ test("$.ajax - xml: non-namespace elements inside namespaced elements", function
 test("$.ajax - preprocess", function() {
 	expect(1);
 	stop();
-	var customHeader = "value-for-custom-header";
+	var customHeader = "value";
 	$.ajax({
 		url: "data/name.php", 
 		data: {'req': true},
-		before: function(xml) {
-			xml.setRequestHeader('customHeader', customHeader)
+		beforeSend: function(xml) {
+			xml.setRequestHeader('X-Custom-Header', customHeader);
 		},
 		success: function(data) {
 			ok( data == customHeader, "check return value, should be the custom header sent" );