var vkApi = new Function();

vkApi.init = function (acccess_token) {
    this.acccess_token = acccess_token;
    this.v = 5.21;
};

vkApi.call = function (method, cb, params) {
    !('acccess_token' in params) && (params.acccess_token = this.acccess_token);
    !('v' in params) && (params.v = this.v);
    var r = new XMLHttpRequest;
    r.open('POST', 'https://api.vk.com/method/' + method)
    r.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    r.onload = function () {
        var o = JSON.parse(r.response);
        console.log(o);
    };
    var q = '';
    for (var i in params) {
        q += (q.length ? '&' : '') + i + '=' + encodeURIComponent(params[i]);
    }
    console.log(q);
    r.send(q);
};