js验证身份证

    var vcity={ 11:"北京",12:"天津",13:"河北",14:"山西",15:"内蒙古",  
                21:"辽宁",22:"吉林",23:"黑龙江",31:"上海",32:"江苏",  
                33:"浙江",34:"安徽",35:"福建",36:"江西",37:"山东",41:"河南",  
                42:"湖北",43:"湖南",44:"广东",45:"广西",46:"海南",50:"重庆",  
                51:"四川",52:"贵州",53:"云南",54:"西藏",61:"陕西",62:"甘肃",  
                63:"青海",64:"宁夏",65:"新疆",71:"台湾",81:"香港",82:"澳门",91:"国外"  
               };  
      
    checkCard = function()  
    {  
        var card = document.getElementById('card_no').value;  
        //是否为空  
        if(card === '')  
        {  
            alert('请输入身份证号，身份证号不能为空');  
            document.getElementById('card_no').focus;  
            return false;  
        }  
        //校验长度，类型  
        if(isCardNo(card) === false)  
        {  
            alert('您输入的身份证号码不正确，请重新输入');  
            document.getElementById('card_no').focus;  
            return false;  
        }  
        //检查省份  
        if(checkProvince(card) === false)  
        {  
            alert('您输入的身份证号码不正确,请重新输入');  
            document.getElementById('card_no').focus;  
            return false;  
        }  
        //校验生日  
        if(checkBirthday(card) === false)  
        {  
            alert('您输入的身份证号码生日不正确,请重新输入');  
            document.getElementById('card_no').focus();  
            return false;  
        }  
        //检验位的检测  
        if(checkParity(card) === false)  
        {  
            alert('您的身份证校验位不正确,请重新输入');  
            document.getElementById('card_no').focus();  
            return false;  
        }  
        alert('OK');  
        return true;  
    };  
      
      
    //检查号码是否符合规范，包括长度，类型  
    isCardNo = function(card)  
    {  
        //身份证号码为15位或者18位，15位时全为数字，18位前17位为数字，最后一位是校验位，可能为数字或字符X  
        var reg = /(^\d{15}$)|(^\d{17}(\d|X)$)/;  
        if(reg.test(card) === false)  
        {  
            alert("demo");  
            return false;  
        }  
      
        return true;  
    };  
      
    //取身份证前两位,校验省份  
    checkProvince = function(card)  
    {  
        var province = card.substr(0,2);  
        if(vcity[province] == undefined)  
        {  
            return false;  
        }  
        return true;  
    };  
      
    //检查生日是否正确  
    checkBirthday = function(card)  
    {  
        var len = card.length;  
        //身份证15位时，次序为省（3位）市（3位）年（2位）月（2位）日（2位）校验位（3位），皆为数字  
        if(len == '15')  
        {  
            var re_fifteen = /^(\d{6})(\d{2})(\d{2})(\d{2})(\d{3})$/;  
            var arr_data = card.match(re_fifteen);  
            var year = arr_data[2];  
            var month = arr_data[3];  
            var day = arr_data[4];  
            var birthday = new Date('19'+year+'/'+month+'/'+day);  
            return verifyBirthday('19'+year,month,day,birthday);  
        }  
        //身份证18位时，次序为省（3位）市（3位）年（4位）月（2位）日（2位）校验位（4位），校验位末尾可能为X  
        if(len == '18')  
        {  
            var re_eighteen = /^(\d{6})(\d{4})(\d{2})(\d{2})(\d{3})([0-9]|X)$/;  
            var arr_data = card.match(re_eighteen);  
            var year = arr_data[2];  
            var month = arr_data[3];  
            var day = arr_data[4];  
            var birthday = new Date(year+'/'+month+'/'+day);  
            return verifyBirthday(year,month,day,birthday);  
        }  
        return false;  
    };  
      
    //校验日期  
    verifyBirthday = function(year,month,day,birthday)  
    {  
        var now = new Date();  
        var now_year = now.getFullYear();  
        //年月日是否合理  
        if(birthday.getFullYear() == year && (birthday.getMonth() + 1) == month && birthday.getDate() == day)  
        {  
            //判断年份的范围（3岁到100岁之间)  
            var time = now_year - year;  
            if(time >= 3 && time <= 100)  
            {  
                return true;  
            }  
            return false;  
        }  
        return false;  
    };  
      
    //校验位的检测  
    checkParity = function(card)  
    {  
        //15位转18位  
        card = changeFivteenToEighteen(card);  
        var len = card.length;  
        if(len == '18')  
        {  
            var arrInt = new Array(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2);  
            var arrCh = new Array('1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2');  
            var cardTemp = 0, i, valnum;  
            for(i = 0; i < 17; i ++)  
            {  
                cardTemp += card.substr(i, 1) * arrInt[i];  
            }  
            valnum = arrCh[cardTemp % 11];  
            if (valnum == card.substr(17, 1))  
            {  
                return true;  
            }  
            return false;  
        }  
        return false;  
    };  
      
    //15位转18位身份证号  
    changeFivteenToEighteen = function(card)  
    {  
        if(card.length == '15')  
        {  
            var arrInt = new Array(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2);  
            var arrCh = new Array('1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2');  
            var cardTemp = 0, i;    
            card = card.substr(0, 6) + '19' + card.substr(6, card.length - 6);  
            for(i = 0; i < 17; i ++)  
            {  
                cardTemp += card.substr(i, 1) * arrInt[i];  
            }  
            card += arrCh[cardTemp % 11];  
            return card;  
        }  
        return card;  
    };