验证身份证号码是否符合规范，格式是否正确，首先要对输入的号码进行验证（包括长度，地区）

$(function(){
   $(".identity").blur(function(){
       $idcard = $("#idCard").val();
       //身份证的地区代码对照  
		var aCity = { 11: "北京",12: "天津",13: "河北",14: "山西",15: "内蒙古",21: "辽宁",22: "吉林",23: "黑龙江",31: "上海",32: "江苏",33: "浙江",34: "安徽",35: "福建",36: "江西",37: "山东",41: "河南",42: "湖北",43: "湖南",44: "广东",45: "广西",46: "海南",50: "重庆",51: "四川",52: "贵州",53: "云南",54: "西藏",61: "陕西",62: "甘肃",63: "青海",64: "宁夏",65: "新疆",71: "台湾",81: "香港",82: "澳门",91: "国外" };           
		//获取证件号码  
		var person_id=$("#idCard").val();  
		//合法性验证  
		var sum = 0;  
		//出生日期  
		var birthday;  
		//验证长度与格式规范性的正则  
		var pattern=new RegExp(/(^\d{15}$)|(^\d{17}(\d|x|X)$)/i);         
		if (pattern.exec(person_id)) {  
			//验证身份证的合法性的正则  
			pattern=new RegExp(/^[1-9]\d{7}((0\d)|(1[0-2]))(([0|1|2]\d)|3[0-1])\d{3}$/);  
			if(pattern.exec(person_id)) {     
				//获取15位证件号中的出生日期并转位正常日期       
				birthday = "19"+person_id.substring(6,8)+"-"+person_id.substring(8,10)+"-"+person_id.substring(10,12);            
			}                 
			else   
			{     
				person_id = person_id.replace(/x|X$/i,"a");                       
				//获取18位证件号中的出生日期  
				birthday =person_id.substring(6,12)+"-"+person_id.substring(12,14);  
				  
				//校验18位身份证号码的合法性  
				for (var i = 17; i >= 0; i--)   
				{  
					sum += (Math.pow(2,i) % 11) * parseInt(person_id.charAt(17 - i),11);  
				}  
				if (sum % 11 != 1) {      
					$(this).addClass("txtrequired");                  
					//alert("身份证号码不符合国定标准，请核对！");     
					$(".error").text("身份证号码不符合国定标准，请核对！").css("height","30px");                          
					//$("#person_id").val("");  
					$("#birthday").val("")                    
					return false;  
				}             
			}  
			//检测证件地区的合法性                                  
			if (aCity[parseInt(person_id.substring(0,2))] == null)   
			{  
				$(this).addClass("txtrequired");  
				//alert("证件地区未知，请核对！"); 
				$(".error").text("证件地区未知，请核对！").css("height","30px");                             
				//$("#person_id").val("");  
				$("#birthday").val("");               
				return false;  
			}  
			var dateStr = new Date(birthday.replace(/-/g,"/"));                  
			  
			//alert(birthday +":"+(dateStr.getFullYear()+"-"+ Append_zore(dateStr.getMonth()+1)+"-"+ Append_zore(dateStr.getDate())))  
			if (birthday != (dateStr.getFullYear()+"-"+ Append_zore(dateStr.getMonth()+1)+"-"+ Append_zore(dateStr.getDate()))) {  
				$(this).addClass("txtrequired");  
				//alert("证件出生日期非法！");  
				$(".error").text("证件出生日期非法！").css("height","30px");                           
				//$("#person_id").val("");  
				$("#birthday").val("");                   
				return false;  
			}  
			$(this).removeClass("txtrequired");  
			$("#birthday").val(birthday);                 
		}  
		else  
		{     
			$(this).addClass("txtrequired");      
			//alert("证件号码格式非法！");                           
			//$("#person_id").val(""); 
			$(".error").text("证件号码格式非法！").css("height","30px");    
			$("#birthday").val("")    
			return false;  
		}             
   });
});