Simple implementation of ID card verification based on javascript_javascript skills

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(card) 
{ 

//是否为空 
if(card === '') 
{ 

return "请输入身份证号，身份证号不能为空"; 
} 
//校验长度，类型 
if(isCardNo(card) === false) 
{ 

return "您输入的身份证号码不正确，请重新输入"; 
} 
//检查省份 
if(checkProvince(card) === false) 
{ 
return "您输入的身份证号码不正确,请重新输入"; 
} 
//校验生日 
if(checkBirthday(card) === false) 
{ 
return "您输入的身份证号码生日不正确,请重新输入"; 
} 
//检验位的检测 
if(checkParity(card) === false) 
{ 
return "您的身份证校验位不正确,请重新输入"; 
} 

return "ok"; 
}; 


//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) 
{ 
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; 
};