card.js

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)
	{
		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;
};

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test.html