post = function(url, params, callback, type) {
    params = (params == "" ? "{}" : params)
    $.ajax({
        type: "POST",
        url: url,
        data: params,
        contentType: "application/json; charset=utf-8",
        dataType: type,
        success: callback
    });
}

serializer = function(form, fields) {
    var serialized = new Array();
    for (x in fields) {
        field = $(form + ' input[name=' + fields[x] + ']').val();
        if (field == null)
            field = $(form + ' select[name=' + fields[x] + ']').val();
        serialized.push("'" + fields[x] + "' : '" + field + "'");
    }
    return '{' + serialized.join(',') + '}';
}