javascript实现验证身份证号的有效性并提示

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; } 

<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>