Danh sách bán hàng

uses crt;
type
  ds=record
    TenHang:string[30];
    DonGia:integer;
    SoLuong:integer;
    ThanhTien:integer;
  end;
var
  a:array[1..50] of ds;
  i,n,tong,chon:integer;
procedure nhap;
begin
  writeln('Nhap gia tri cua n:');
  readln(n);
  tong:=0;
  for i:=1 to n do
    begin
       write('Ten Hang:');
       readln(a[i].TenHang);
       write('Don Gia:');
       readln(a[i].DonGia);
       write('So Luong:');
       readln(a[i].Soluong);
       a[i].ThanhTien:= a[i].SoLuong*a[i].DonGia ;
       tong:=tong+a[i].ThanhTien;
   end;
end;
procedure xuat;
begin
   writeln('STT':5,'Ten Hang':15,'Don Gia':15,'So Luong':15,'Thanh Tien':20);
     for i:=1 to n do
       writeln(i:4,a[i].TenHang:15,a[i].DonGia:15,a[i].SoLuong:15,a[i].ThanhTien:20);
       writeln('Tong Tien' :50, tong:5);
   readln;
end;
begin
  clrscr;
  repeat
    writeln('Moi chon phim chuc nang');
    writeln('  1. Nhap');
    writeln('  2. Xuat');
    writeln('  3. Thoat');
    readln(chon);
    case chon of
      1: nhap;
      2: xuat;
    end;
  until chon=3;
end.