easyui datebox只显示年月

$("#beginMonth").datebox({
            formatter: function(date) {
                debugger;
                var y = date.getFullYear();
                var m = date.getMonth() + 1;
                return y + '-' + (m < 10 ? ('0' + m) : m);
            },
            parser: function(s) {
                debugger;
                if (!s) {
                    return new Date();
                }
                var ss = s.split('-');
                var y = parseInt(ss[0], 10);
                var m = parseInt(ss[1], 10);
                if (!isNaN(y) && !isNaN(m)) {
                    return new Date(y, m - 1);
                } else {
                    return new Date();
                }
            }
        });