var username = 'luceed_mb';
var password = '7e5y2Uza';
var restAuth = 'bHVjZWVkX21iOjdlNXkyVXph';
var xhr = new XMLHttpRequest();
xhr.open("GET", "http://apidemo.luceed.hr/datasnap/rest/artikli/naziv/" + "a" + "/%5b0,100%5d", false);
xhr.setRequestHeader({
  'Content-Type': 'application/javascript',
  'Authorization': 'Basic' + btoa(username + ':' + password)
});
xhr.send();