文本框中的值只能爲數字或者是小數

//判斷輸入小計金額的文本框中的值只能爲數字或者是小數
$(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 不能使用退格鍵 
            {
                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, "");
            //必須保證第一個爲數字而不是.
            this.value = this.value.replace(/^\./g, "");
            //保證只有出現一個.而沒有多個.
            this.value = this.value.replace(/\.{2,}/g, ".");
            //保證.只出現一次，而不能出現兩次以上
            this.value = this.value.replace(".", "$#$").replace(/\./g, "").replace("$#$", ".");
        });
    };
    $("#要輸入數字或者小數文本框的id").numeral();
});