QML XMLHttpRequest.status does not return OK value

} else if (doc.readyState == XMLHttpRequest.DONE) {               
    if (doc.status == 200) { // check the status, 200 = OK                       
        var a = doc.responseXML.documentElement;                  
        for (var ii = 0; ii < a.childNodes.length; ++ii) {        
            showRequestInfo(a.childNodes[ii].nodeName);           
        }                                                         
        showRequestInfo("Headers -->");                           
        showRequestInfo(doc.getAllResponseHeaders ());            
        showRequestInfo("Last modified -->");                     
        showRequestInfo(doc.getResponseHeader ("Last-Modified")); 
    } else { // status NOK
        showRequestInfo("ERROR, status: " + doc.status);          
    }                                                             
}