function SwedishSocialSecurityNumber(socialSecurityNumber){
    this.isOver100 = false;
    this.socialSecurityNumber = socialSecurityNumber;


    if(!this.hasTheRightPattern())
        throw new Error('The SSN has to have the format YYMMDD-XXXX or YYMMDD+XXXX');

    this.year = parseInt(this.socialSecurityNumber.substring(0,2));
    this.month = parseInt(this.socialSecurityNumber.substring(2,4));
    this.day = parseInt(this.socialSecurityNumber.substring(4,6));
    this.code = parseInt(this.socialSecurityNumber.substring(7,11));

    if(this.socialSecurityNumber.substring(6, 7) == '+') this.isOver100 = true;

    if(!this.isDateValid(this.getFullYear(), this.month, this.day))
        throw new Error('The given date is not valid');

    if(this.getCheckSum() != this.socialSecurityNumber.substring(10,11))
        throw new Error("The control number is invalid");

}


SwedishSocialSecurityNumber.prototype.getFullYear = function(){
    currentYear = new Date().getFullYear();
    ret = 0;
    if(this.year < 10){
        ret = currentYear.toString().substring(0,2) + "0" + this.year.toString();
    } else {
        ret = currentYear.toString().substring(0,2) +  this.year.toString();
    }

    if(this.isOver100) return parseInt(ret) - 100;
    if( parseInt(ret) > currentYear ) return parseInt(ret) - 100;

    return(parseInt(ret));

};

SwedishSocialSecurityNumber.prototype.getCheckSum = function(){
    variegated = 2;
    temp = 0;
    list = [];

    for(i = 0; i < this.socialSecurityNumber.length - 1; i++){
        if( i == 6) continue;

        temp = parseInt(this.socialSecurityNumber[i]);
        temp = temp * variegated;
        tempStr = temp.toString();
        for(j = 0; j < tempStr.length; j++) {
            list.push(parseInt(tempStr[j]));
        }

        variegated = variegated == 2 ? 1 : 2;
        temp = 0;
    }

    sum = 0;
    for(i = 0; i < list.length; i++) sum = sum + list[i];

    return(10 - (sum % 10));
};

SwedishSocialSecurityNumber.prototype.hasTheRightPattern = function(){
    pattern = /^[0-9]{2}[0-1][0-9][0-3][0-9][-|+][0-9]{4}$/
    return pattern.test(this.socialSecurityNumber);
};

SwedishSocialSecurityNumber.prototype.isDateValid = function(){
    d = new Date(this.getFullYear(), this.month - 1, this.day);
    if(isNaN(d)) return false;
    if(d.getFullYear() == this.getFullYear() && (d.getMonth() + 1) == this.month && d.getDate() == this.day) return true;
    return false;
};

SwedishSocialSecurityNumber.prototype.isFemale = function() {
    if((parseInt(this.socialSecurityNumber.substring(9, 10)) % 2) === 0) return true;
    return false;
};

SwedishSocialSecurityNumber.prototype.isMale = function() {
    return !this.isFemale();
};