Cors ajax

function makeRequest() {
    var username = document.getElementById('username');
    var password = document.getElementById('password');
    var url = "http://api.someserver.com";
    var body = '<?xml version="1.0" encoding="UTF-8"?>' +
                '<env:Envelope xmlns:env="http://www.w3.org/2003/05/soap-envelope" ' +
                'xmlns:ns1="urn:StartAJob.Intf-IStartAJob" xmlns:xsd="http://www.w3.org/2001/XMLSchema" ' +
                'xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" ' +
                'xmlns:enc="http://www.w3.org/2003/05/soap-encoding">' +
                '<env:Body><ns1:Login env:encodingStyle="http://www.w3.org/2003/05/soap-encoding">' +
                '<UserName xsi:type="xsd:string">' + username + '</UserName><Password xsi:type="xsd:string">' + password + '</Password>' +
                '<IP xsi:type="xsd:string"></IP></ns1:Login></env:Body></env:Envelope>';
    var xhttp = new XMLHttpRequest();
    xhttp.open("POST", url, true);
 
    if (!xhttp) {
        document.getElementById("response").innerHTML = "not supported";
        return;
    }
 
    xhttp.onload = function() {
        document.getElementById("response").innerHTML = xhttp.responseText;
    };
 
    xhttp.onerror = function() {
        document.getElementById("response").innerHTML = 'There was an error making response';
    };
 
    xhttp.setRequestHeader("Content-type", "text/xml");
    xhttp.send(body);
}