文本框中的值只能为数字或者是小数

//判断输入小计金额的文本框中的值只能为数字或者是小数
$(function () {
$.fn.numeral = function () {
        $(this).css("ime-mode", "disabled");
        this.bind("keypress", function (e) {
            var code = (e.keyCode ? e.keyCode : e.which);  //兼容火狐 IE  
            if (!$.browser.msie && (e.keyCode == 0x8))  //火狐下 不能使用退格键 
            {
                return;
            }
            return code >= 48 && code <= 57 || code == 46;

        });
        this.bind("blur", function () {

            if (this.value.lastIndexOf(".") == (this.value.length - 1)) {
                this.value = this.value.substr(0, this.value.length - 1);
            } else if (isNaN(this.value)) {
                this.value = " ";
            }
        });
        this.bind("paste", function () {
            var s = clipboardData.getData('text');
            if (!/\D/.test(s));
            value = s.replace(/^0*/, '');
            return false;
        });
        this.bind("dragenter", function () {
            return false;
        });
        this.bind("keyup", function () {
            this.value = this.value.replace(/[^\d.]/g, "");
            //必须保证第一个为数字而不是.
            this.value = this.value.replace(/^\./g, "");
            //保证只有出现一个.而没有多个.
            this.value = this.value.replace(/\.{2,}/g, ".");
            //保证.只出现一次，而不能出现两次以上
            this.value = this.value.replace(".", "$#$").replace(/\./g, "").replace("$#$", ".");
        });
    };
    $("#要输入数字或者小数文本框的id").numeral();
});