Background
Worldwide Bank want to produce a simple program that consultants can use to help, advise and inform potential customers, as described in the scenario below. The program must be able to run on a low specification laptop/tablet with a portable printer, but no internet access facilities should be required.

Scenario
The bank employs consultants who visit clients in their home or workplace. During these visits, they use a laptop computer or tablet to demonstrate the advantages of the financial products offered by the bank, and print a statement for the customer to keep. The Bank has introduced a new investment account, and want software for consultants to use that will quickly show potential clients how their investments will perform using this new account.

The account requires clients to invest money for an agreed period, during which time interest will be gained. At the end of the investment period, a final bonus will be added. The amount of this bonus will depend on the final balance of the account at the end of the investment period, including all interest gained.

A client can invest any sum of money between £500 and £30,000 for a fixed term period of between 1 and 15 years. During the investment period, no additional money can be invested, and no money can be withdrawn.

• The consultant will need to enter the amount to be invested and the investment term. If figures outside the specified ranges are input to the program, they must be rejected and a suitable error message displayed. On clearing the error message, the program must then be reset to allow the input of new figures.

• Interest is calculated using compound interest at a fixed rate of 4% per annum. In other words, at the end of each year the interest for that year is added to the capital.

• At the end of the next year interest is gained both on the original capital and the interest gained in the previous years.

• At the end of the final year, a bonus is gained depending on the final capital, as shown in the table below –

Capital at end of investment term Bonus gained
Less than £5000 1% of final capital
£5000 - £7500 2 % of final capital
Over £7500 3% of final capital

• The program must display the final capital and the bonus and a statement of the year by year balance for the account.