#include <iostream>
#include <string>
using namespace std;
int i=1;
struct Book{
  char name;
  int ID;
  int price;
  struct date;
}; Book b[20];
struct Date{
  int year;
  int month;
  int day;
};

   voivoid add()
   {

cout<<"输入书的名字，ID，价格，出版日期。\n";
   cin>> b[i].name>> b[i].ID>> b[i].price>> b[i].date.year>> b[i].date.month>> b[i].date.day;
   }
   void putdown()
   {int k,j;char name[20];
    cout<<"输入书的名字\n";
    cin>>name;
    for(j=1;j<i;j++)
    {if(strcmp(name,b[j].name)==0)
    break;}

cout<<"把 "<<b[j].name<<" 从书篮中拿出";
     for(k=j+1;k<i;k++){b[k-1]=b[k];}
    i--;
   }
   
    void search_the_highest()
 {
   int max=0; int j;
   for(j=1;j<=i;j++){if (b[j].price>max) max=b[j].price;}
      for(j=1;j<=i;j++)
   {
  if (b[j].price==max)
  {cout<<"最贵的书是:\n"; cout<<"名字:"<<b[j].name  <<"ID:"<<b[j].ID <<"价格:"<<b[j].price <<"出版日期:"<<
  b[j].date.year<<'-'<<b[j].date.month<<'-'<<b[j].date.day;
  }
   }

 }

      int search_the_total_money()
    {int total=0;int j;
      for(j=1;j<=i;j++){total+=b[j].price;}
   return total;

}
     
      int main()
   {
    int select;
    while (1)
    {
    cout<<"1.添加一本书.\n";
    cout<<"2.放下一本书.\n";
    cout<<"3.查询最贵的书.\n";
    cout<<"4.查询当前书篮中书的总价.\n";
    cout<<"5.退出\n";
   
    cin>>select;
   
       switch(select)
    {
        case 1:add();i++;break;
        case 2:putdown();break;
        case 3:search_the_highest();break;
        case 4:search_the_total_money();break;
        case 5:return 0;
   
    }
    }
   }
错误
E:\程序源代码2\Cpp1.cpp(17) : error C2146: syntax error : missing ';' before identifier 'add'
E:\程序源代码2\Cpp1.cpp(17) : error C2501: 'voivoid' : missing storage-class or type specifiers
E:\程序源代码2\Cpp1.cpp(17) : fatal error C1004: unexpected end of file found
Error executing cl.exe.
求大神解答