I please need your help with this compound interest program.

What I need to do is:

"Create an application which calculates compound interest on a deposit over a certain period of time -

1. Display the amount of money over the years on a graph. The x-axis should show the number of years, and the y-axis should show the amount of money.

2. Using a thread, display each year and the amount as a point on the graph with a label. Display point about 200 milliseconds apart. The program should loop infinitely.

3. The number of years and the amount must be entered by the user as command arguments. The number of years must range from 1 - 25 and the deposit from 20 - 200.

4. Interest will be 5% per annum
5. Provide error checking for the input boxes.
"

The code that Iv'e done so far is:

I know that the formula for this is:
amount = prevAmount + (prevAmount*interest)

but that's about it. I'm not sure what to do further and if my code is correct this far.