void add()
{


	HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
		int sign;
		char ch;
		f = fopen(name, "r+b");
		fread(&list, sizeof(struct product), n, f);
		int j = n;
		do
		{
			SetConsoleTextAttribute(hConsole, (WORD)((15 << 4) | 4));
			printf("Input type of product: 1- drink 2-chocolate: ");
			SetConsoleTextAttribute(hConsole, (WORD)((15 << 4) | 0));
			scanf("%d", &sign);
			if (sign == 1) list[j].tag = DRINK;
			else list[j].tag = CHOCOLATE;
			switch (list[j].tag)
			{
			case DRINK:
			{  printf("name of drink: ");
			scanf("%s", list[j].name);
			printf("Enter calor of drink: ");
			scanf("%d", &list[j].calor);
			printf("Enter value of drink: ");
			scanf("%d", &list[j].value);
			printf("Enter strength of drink: ");
			scanf("%d", &list[j].drink.strength); break;
			}
			case CHOCOLATE:
			{
							  printf("Enter name of chocolate:");
							  scanf("%s", list[j].name);
							  printf("Enter calor of chocolate: ");
							  scanf("%d", &list[j].calor);
							  printf("Enter value of chocolate: ");
							  scanf("%d", &list[j].value);
							  printf("Enter weigth of chocolate: ");
							  scanf("%d", &list[j].chocolate.weigth);
							  printf("Enter filling of chocolate: ");
							  scanf("%s", list[j].chocolate.filling); break;
			}
			}   //end of switch
			SetConsoleTextAttribute(hConsole, (WORD)((15 << 4) | 2));
			printf("Continue? [y/n] ");
			SetConsoleTextAttribute(hConsole, (WORD)((15 << 4) | 0));
			getchar();
			ch = getchar();
			j++;
		} while ((ch != 'n') && (ch != 'N'));
		fclose(f);
		n = j;
		f = fopen(name, "r+b");
		for (j = 0; j < n; j++)
		{
			fwrite(&list[j],sizeof(struct product),1,f);
		}
		fclose(f);

}