1] 授業単元： レポート
[2] 問題文(含コード&リンク)：
Create an invoice object that contains all the information necessary to process one line of

an invoice. Assume that the invoice must include the following data and functions.

Data:
Quantity Ordered
Quantity Shipped
Part Number
Part Description
Unit Price
Sales Tax Rate
Sales tax Amount
Shipping
Total

Functions:
* A function to initialize all the data items to 0, except the Sales Tax Rate, which should be initialized to 5%.
* A function to allow the user to initialize all the data items from the keyboard.
* A function to calculate the Extended Price of the item.
* A function to calculate the Sales Tax Amount of the item.
* A function to calculate the Total Amount of the invoice.
* A function to display the invoice data with header information in a businesslike format.

[3] 環境
　[3.1] OS：WindowsXP
　[3.2] コンパイラ(バージョン)：
　[3.3] 言語：C++
[4] 期限：7月26日まで
[5] C++は，初めて触るので知識ないに等しいです．いろいろ調べてるうちにこのスレにたどり着きました．よろしくお願いします．