Simple JavaScript counter

function counterf(value) {
    return {
        inc: function () {
            return value += 1;
        },
        dec: function () {
            return value -= 1;
        }
    };
}

var counter = counterf(10);
counter.inc()  // 11
counter.dec()  // 10

JSFiddle: http://jsfiddle.net/stevenhollidge/f9sKV/