jQuery set Headers for $.ajax

gistfile1.js

// jQuery Headers support for $.ajax

$.ajax({
        beforeSend: function(xhrObj){
                xhrObj.setRequestHeader("Content-Type","application/json");
                xhrObj.setRequestHeader("Accept","application/json");
        }
        type: "POST",
        url: "/article",
        processData: false,
        data: jsonData,
        dataType: "json",
        success: function(json){
                do something...
        }
});

I'm trying this:

$.ajax({
headers: {
Accept : "text/javascript; charset=utf-8",
"Content-Type": "text/javascript; charset=utf-8"
},
type: "GET", url: rootURL, dataType: "jsonp",
beforeSend: function(xhr){
xhr.setRequestHeader('Access-Control-Allow-origin', 'true');
},
//jsonp: false,
//jsonpCallback: 'eval',
success: function(data) {
console.log(data);
},
error: function(jqXHR, msg, erro){
console.log(erro);
}
});

But the request is going:

Accept: /

HELP!!

hello i think only the server can set 'Access-Control-Allow-origin' @lazaropj