dotjs-ify my greasemonkey user scripts

default.js

function GM_getValue (key) {
    var value = localStorage.getItem('GM_'.key);
    if ('undefined' == typeof(value)) {
        return;
    }
    return value;
}

function GM_setValue (key, value) {
    localStorage.setItem('GM_'.key, value);
    return value;
}


function GM_log (logs) {
    console.log(logs);
}

function GM_registerMenuCommand () {
    // IMPREMENT ME
    return;
}

function GM_xmlhttpRequest (args) {
	var xhr = new XMLHttpRequest();
    xhr.open(args.method, args.url, true);
    if (args.overrideMimeType) xhr.overrideMimeType(args.overrideMimeType);
    
    xhr.onreadystatechange = function (aEvt) {
        if (xhr.readyState == 4) {
            if(xhr.status == 200) {
                if (args.onload) args.onload(xhr);
            }
            else {
                if (args.onerror) args.onerror(xhr);
            }
        }
    };
    
    xhr.send(null);
}