//身份证号合法性验证

    //支持15位和18位身份证号

    //支持地址编码、出生日期、校验位验证

    function IdentityCodeValid(code) {

        var city={

            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 "};

        var tip = "";

        var pass= true;

        if(!code || !/^\d{6}(18|19|20)?\d{2}(0[1-9]|1[12])(0[1-9]|[12]\d|3[01])\d{3}(\d|X)$/i.test(code)){

            tip = "身份证号格式错误";

            pass = false;

        }

        else if(!city[code.substr(0,2)]){

            tip = "地址编码错误";

            pass = false;

        }

        else{

            //18位身份证需要验证最后一位校验位

            if(code.length == 18){

                code = code.split('');

                //∑(ai×Wi)(mod 11)

                //加权因子

                var factor = [ 7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2 ];

                //校验位

                var parity = [ 1, 0, 'X', 9, 8, 7, 6, 5, 4, 3, 2 ];

                var sum = 0;

                var ai = 0;

                var wi = 0;

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

                {

                    ai = code[i];

                    wi = factor[i];

                    sum += ai * wi;

                }

                var last = parity[sum % 11];

                if(parity[sum % 11] != code[17]){

                    tip = "校验位错误";

                    pass =false;

                }

            }

        }

        if(!pass) alert(tip);

        return pass;

    }

    var c = '130981199312253466';

    var res= IdentityCodeValid(c);

function checkId($id) {

    $len = strlen($id);

    if($len != 18) {

        return 0;

    }

    $a=str_split($id,1);

    $w=array(7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2);

    $c=array(1,0,'X',9,8,7,6,5,4,3,2);

    $sum = 0;

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

            $sum= $sum + $a[$i]*$w[$i];

    }

    $r=$sum%11;

    $res=$c[$r];

    //echo "校验位是: ".$res;

    if ($res == $a[17]) {

        return 1;

    } else {

        return 0;

    }

}