只能输入数字

    $(function () {
        $("#keyword").keyup(function () {
            var r = /^\d+\.?\d*$/;
            var obj = $("#keyword");
            if (!r.test(obj.val())) {
                var s = parseInt(obj.val());
            // var s = parseFloat(obj.val());
                if (isNaN(s)) {
                    obj.val("");
                } else {
                    obj.val(s);
                }
            }
        });