function request(url, data, onSuccessCallback){
    ajax('get', url, data, onSuccessCallback)
}

function update(url, data, onSuccessCallback) {
    if (data) {
        data = $.toJSON(data)
    }
    ajax('PUT', url, data, onSuccessCallback)
}

function ajax(method, url, data, onSuccessCallback) {
    $.ajax({
        url: url,
        type: method,
        dataType: 'json',
        contentType: 'application/json',
        data: data,
        cache: false,
        success: function(data, textStatus, jqXHR){
            if (onSuccessCallback) {
                onSuccessCallback(data);
            }
        },
        error: function(jqXHR, textStatus, errorThrown) {
            if (existsStatusBar ){
                showIntoStatusBar(jqXHR.responseText)
            }else{
                alert('Erro (ajax) - ' + jqXHR.responseText)
            }
        }
    });
}