身份證正則

function check_cd_card(){
                    var oTxt=document.getElementById('cd_code');
                    var CheckIdCard={  
                    //Wi 加權因子 Xi 餘數0~10對應的校驗碼 Pi省份代碼
                    Wi:[7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2],
                    Xi:[1,0,"X",9,8,7,6,5,4,3,2],
                    Pi:[11,12,13,14,15,21,22,23,31,32,33,34,35,36,37,41,42,43,44,45,46,50,51,52,53,54,61,62,63,64,65,71,81,82,91],

                    //檢驗18位身份證號碼出生日期是否有效
                    //parseFloat過濾前導零，年份必需大於等於1900且小於等於當前年份，用Date()對象判斷日期是否有效。
                    brithday18:function(sIdCard){
                        var year=parseFloat(sIdCard.substr(6,4));
                        var month=parseFloat(sIdCard.substr(10,2));
                        var day=parseFloat(sIdCard.substr(12,2));
                        var checkDay=new Date(year,month-1,day);
                        var nowDay=new Date();
                        if (1900<=year && year<=nowDay.getFullYear() && month==(checkDay.getMonth()+1) && day==checkDay.getDate()) {
                            return true;
                        };
                    },

                    //檢驗15位身份證號碼出生日期是否有效  
                    brithday15:function(sIdCard){
                        var year=parseFloat(sIdCard.substr(6,2));
                        var month=parseFloat(sIdCard.substr(8,2));
                        var day=parseFloat(sIdCard.substr(10,2));
                        var checkDay=new Date(year,month-1,day);
                        if (month==(checkDay.getMonth()+1) && day==checkDay.getDate()) {
                            return true;
                        };
                    },

                    //檢驗校驗碼是否有效  
                    validate:function(sIdCard){
                        var aIdCard=sIdCard.split("");
                        var sum=0;
                        for (var i = 0; i < CheckIdCard.Wi.length; i++){
                            sum+=CheckIdCard.Wi[i]*aIdCard[i]; //線性加權求和
                        };
                        var index=sum%11;//求模，可能爲0~10,可求對應的校驗碼是否於身份證的校驗碼匹配
                        if (CheckIdCard.Xi[index]==aIdCard[17].toUpperCase()) {
                            return true;
                        };
                    },

                    //檢驗輸入的省份編碼是否有效
                            province:function(sIdCard){
                                var p2=sIdCard.substr(0,2);
                                for (var i = 0; i < CheckIdCard.Pi.length; i++){
                                    if(CheckIdCard.Pi[i]==p2){
                                        return true;
                                    };
                                };
                            }
                        };


                    var sIdCard=oTxt.value.replace(/^\s+|\s+$/g,"");//去除字符串的前後空格，允許用戶不小心輸入前後空格
                if (sIdCard.match(/^\d{14,17}(\d|X)$/gi)==null) {//判斷是否全爲18或15位數字，最後一位可以是大小寫字母X
                    alert("身份證號碼須爲18位或15位數字");      //允許用戶輸入大小寫X代替羅馬數字的Ⅹ
                    return false;
                }else if (sIdCard.length==18) {
                    if (CheckIdCard.province(sIdCard)&&CheckIdCard.brithday18(sIdCard)&&CheckIdCard.validate(sIdCard)) {
                        return true;
                    }
                    else{
                        alert("請輸入有效的身份證號碼");
                        return false;
                    };
                }else if (sIdCard.length==15) {
                    if (CheckIdCard.province(sIdCard)&&CheckIdCard.brithday15(sIdCard)) {
                        return true;
                    }
                    else{
                        alert("請輸入有效的身份證號碼");
                        return false;
                    };
                };
            }