使用Ajax的跨域请求 - 状态码0

Question

我正在尝试使用Ajax进行跨域请求，并且服务器支持它，我添加了以下响应头：

Access-Control-Allow-Origin: *
Access-Control-Allow-Headers: *
Access-Control-Allow-Methods: GET,POST,OPTIONS

但是，XMLHttpRequest的状态代码仍为0，表示跨域请求失败。我正在使用Firefox 15.0.1，这是最新版本，所以它应该支持它。 谁能告诉我我在这里缺少什么？

这是我的代码：

        function getAjaxObject(crossRequest)
        {
            if ((crossRequest)&&(window.XDomainRequest))
            {
                var domainRequestObject=new window.XDomainRequest();
                domainRequestObject.onload=function() { };
                domainRequestObject.onprogress=function() { };
                domainRequestObject.ontimeout=function() { };
                domainRequestObject.onerror=function() { };
                return domainRequestObject;
            }
            else if (window.XMLHttpRequest!=null) return new XMLHttpRequest();
            else return new ActiveXObject("Microsoft.XMLHTTP");
        }

        function sendOperationRequest(requestPath,requestXML,readyFunction,loadFunction)
        {
            ajaxObject=getAjaxObject(true);
            if (window.XDomainRequest) ajaxObject.onload=loadFunction;
            else ajaxObject.onreadystatechange=readyFunction;
            //console.log(ajaxObject.onload);
            ajaxObject.open("POST",requestAddress + requestPath,true);
            if (!window.XDomainRequest)
            {
                ajaxObject.setRequestHeader("Content-Type","application/xml");
                ajaxObject.setRequestHeader("Content-Length",requestXML.length);
            }
            else ajaxObject.contentType="application/xml";
            ajaxObject.send(requestXML);
        }

        function login()
        {
            var username=document.getElementById("usernameInput").value;
            var password=document.getElementById("passwordInput").value;
            if (username=="") alert("Please enter the user name.");
            else if (password=="") alert("Please enter the password.");
            else sendOperationRequest("BackOfficeLoginServlet?UTF-8=\"yes\"",
                    "<backoffice-login-request user-name=\"" + username + "\" user-password=\"" + 
                    password + "\" business-entity-id=\"" + businessEntity + "\"/>",
                    loginReadyStateChanged,handleLoginResponse);
        }

        function loginReadyStateChanged()
        {
            if (ajaxObject.readyState==4)
            {
                console.log(ajaxObject.status);
                if (ajaxObject.status==200) handleLoginResponse();
                else if (ajaxObject.status!=0) 
                {
                    alert("There is a connection problem. Make sure you " +
                            "are online and try again.");
                }
            }
        }

这是一个指向日志文件的链接： https://skydrive.live.com/redir?resid=D3F36D33272D62D0!107