身份證號碼之js驗證

//驗證身份證號碼
function checkSecondIdcard(idcard) {
    idcard = idcard.toString();
    //var Errors=new Array("驗證通過!","身份證號碼位數不對!","身份證號碼出生日期超出範圍或含有非法字元!","身份證號碼校驗錯誤!","身份證地區非法!");
    var Errors = new Array(true, false, false, false, false);
    var area = {
        11: "北京",
        12: "天津",
        13: "河北",
        14: "山西",
        15: "內蒙古",
        21: "遼寧",
        22: "吉林",
        23: "黑龍江",
        31: "上海",
        32: "江蘇",
        33: "浙江",
        34: "安徽",
        35: "福建",
        36: "江西",
        37: "山東",
        41: "河南",
        42: "湖北",
        43: "湖南",
        44: "廣東",
        45: "廣西",
        46: "海南",
        50: "重慶",
        51: "四川",
        52: "貴州",
        53: "雲南",
        54: "西藏",
        61: "陝西",
        62: "甘肅",
        63: "青海",
        64: "寧夏",
        65: "新疆",
        71: "臺灣",
        81: "香港",
        82: "澳門",
        91: "國外"
    }
    var idcard, Y, JYM;
    var S, M;
    var idcard_array = new Array();
    idcard_array = idcard.split("");
    //地區檢驗
    if (area[parseInt(idcard.substr(0, 2))] == null) return Errors[4];
    //身份號碼位數及格式檢驗
    switch (idcard.length) {
        case 18:
            //18 位身份號碼檢測
            //出生日期的合法性檢查
            //閏年月日:((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|[1-2][0-9]))
            //平年月日:((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|1[0-9]|2[0-8]))
            if (parseInt(idcard.substr(6, 4)) % 4 == 0 || (parseInt(idcard.substr(6, 4)) % 100 == 0 && parseInt(idcard.substr(6, 4)) % 4 == 0 )) {
                ereg = /^[1-9][0-9]{5}19[0-9]{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|[1-2][0-9]))[0-9]{3}[0-9Xx]$/;//閏年出生日期的合法性正規表示式
            } else {
                ereg = /^[1-9][0-9]{5}19[0-9]{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|1[0-9]|2[0-8]))[0-9]{3}[0-9Xx]$/;//平年出生日期的合法性正規表示式
            }
            if (ereg.test(idcard)) {//測試出生日期的合法性
                //計算校驗位
                S = (parseInt(idcard_array[0]) + parseInt(idcard_array[10])) * 7
                    + (parseInt(idcard_array[1]) + parseInt(idcard_array[11])) * 9
                    + (parseInt(idcard_array[2]) + parseInt(idcard_array[12])) * 10
                    + (parseInt(idcard_array[3]) + parseInt(idcard_array[13])) * 5
                    + (parseInt(idcard_array[4]) + parseInt(idcard_array[14])) * 8
                    + (parseInt(idcard_array[5]) + parseInt(idcard_array[15])) * 4
                    + (parseInt(idcard_array[6]) + parseInt(idcard_array[16])) * 2
                    + parseInt(idcard_array[7]) * 1
                    + parseInt(idcard_array[8]) * 6
                    + parseInt(idcard_array[9]) * 3;
                Y = S % 11;
                M = "F";
                JYM = "10X98765432";
                M = JYM.substr(Y, 1);//判斷校驗位
                if (M == idcard_array[17]) return Errors[0]; //檢測ID的校驗位
                else return Errors[3];
            }
            else return Errors[2];
            break;
        default:
            return Errors[1];
            break;
    }
}