function isIdCardNo(num) {

    var factorArr = new Array(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2, 1);

    var parityBit = new Array("1", "0", "X", "9", "8", "7", "6", "5", "4", "3", "2");

    var varArray = new Array();

    var intValue;

    var lngProduct = 0;

    var intCheckDigit;

    var intStrLen = num.length;

    var idNumber = num;

    // initialize

    if ((intStrLen != 15) && (intStrLen != 18)) {

        return false;

    }

    // check and set value

    for (i = 0; i < intStrLen; i++) {

        varArray[i] = idNumber.charAt(i);

        if ((varArray[i] < '0' || varArray[i] > '9') && (i != 17)) {

            return false;

        } else if (i < 17) {

            varArray[i] = varArray[i] * factorArr[i];

        }

    }

    if (intStrLen == 18) {

        //check date

        var date8 = idNumber.substring(6, 14);

        if (isDate8(date8) == false) {

            return false;

        }

        // calculate the sum of the products

        for (i = 0; i < 17; i++) {

            lngProduct = lngProduct + varArray[i];

        }

        // calculate the check digit

        intCheckDigit = parityBit[lngProduct % 11];

        // check last digit

        if (varArray[17] != intCheckDigit) {

            return false;

        }

    }

    else {        //length is 15

        //check date

        var date6 = idNumber.substring(6, 12);

        if (isDate6(date6) == false) {

            return false;

        }

    }

    return true;

}

function isDate6(sDate) {

    if (!/^[0-9]{6}$/.test(sDate)) {

        return false;

    }

    var year, month, day;

    year = sDate.substring(0, 4);

    month = sDate.substring(4, 6);

    if (year < 1700 || year > 2500) return false

    if (month < 1 || month > 12) return false

    return true

}

/**

 * 判断是否为“YYYYMMDD”式的时期

 *

 */

function isDate8(sDate) {

    if (!/^[0-9]{8}$/.test(sDate)) {

        return false;

    }

    var year, month, day;

    year = sDate.substring(0, 4);

    month = sDate.substring(4, 6);

    day = sDate.substring(6, 8);

    var iaMonthDays = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]

    if (year < 1700 || year > 2500) return false

    if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) iaMonthDays[1] = 29;

    if (month < 1 || month > 12) return false

    if (day < 1 || day > iaMonthDays[month - 1]) return false

    return true

}