JS验证身份证有效性

页面：
效果为输入身份证号，焦掉移开后自动验证，并返回信息！

    <input type="text" class="reg_txt" value="身份证号" titles="请输入您的身份证号！" name="userid" id="username" maxlength="40" onfocus="if(this.value=='身份证号'){this.value='';}" onblur="if(this.value==''){this.value='身份证号';}nunber(this.value);" style="border: 1px solid red;"><br>     <span class="c_red" id="span_username"></span> 

JS：

    function nunber(allowancePersonValue){      if(allowancePersonValue=="身份证号"){       $("#span_username").show();       $("#span_username").html("身份证号不能为空");       return false;      }      //校验长度，类型      else if(isCardNo(allowancePersonValue) === false)      {     $("#span_username").show();       $("#span_username").html("您输入的身份证号码不正确，请重新输入");       return false;      }      //检查省份      else if(checkProvince(allowancePersonValue) === false)      {       $("#span_username").show();       $("#span_username").html("您输入的身份证号码不正确,请重新输入");       return false;      }      //校验生日      else if(checkBirthday(allowancePersonValue) === false)      {       $("#span_username").show();       $("#span_username").html("您输入的身份证号码生日不正确,请重新输入");       return false;      }      //检验位的检测      else if(checkParity(allowancePersonValue) === false)      {       $("#span_username").show();       $("#span_username").html("您的身份证校验位不正确,请重新输入");       return false;      }else{       $("#span_username").hide();       return true;      }     }     //身份证省的编码     var vcity={ 11:"北京",12:"天津",13:"河北",14:"山西",15:"内蒙古",             21:"辽宁",22:"吉林",23:"黑龙江",31:"上海",32:"江苏",             33:"浙江",34:"安徽",35:"福建",36:"江西",37:"山东",41:"河南",             42:"湖北",43:"湖南",44:"广东",45:"广西",46:"海南",50:"重庆",             51:"四川",52:"贵州",53:"云南",54:"西藏",61:"陕西",62:"甘肃",             63:"青海",64:"宁夏",65:"新疆",71:"台湾",81:"香港",82:"澳门",91:"国外"            };     //检查号码是否符合规范，包括长度，类型     function isCardNo(card){      //身份证号码为15位或者18位，15位时全为数字，18位前17位为数字，最后一位是校验位，可能为数字或字符X      var reg = /(^\d{15}$)|(^\d{17}(\d|X)$)/;      if(reg.test(card) === false){       //alert("demo");       return false;      }      return true;     }     //取身份证前两位,校验省份     function checkProvince(card){      var province = card.substr(0,2);      if(vcity[province] == undefined){       return false;      }      return true;     }     //检查生日是否正确     function checkBirthday(card){      var len = card.length;      //身份证15位时，次序为省（3位）市（3位）年（2位）月（2位）日（2位）校验位（3位），皆为数字      if(len == '15'){           var re_fifteen = /^(\d{6})(\d{2})(\d{2})(\d{2})(\d{3})$/;          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     function verifyBirthday(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     function checkParity(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     function changeFivteenToEighteen(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;     }