I have been stuck on a problem in my Intro to Applied Programming course for days now, we use Ruby. The question is:

I have been stuck on a problem in my Intro to Applied Programming course for days now, we use Ruby. The question is: Create program that subtracts a withdrawal from a Savings Account, and returns the following on the Screen (include text as well as calculations): Starting Balance (This is decided by you), Amount Withdrawn (User Input), Interest Accrued (this is earned before the Withdrawal), and Ending Balance. If the withdrawal amount is greater than the Starting balance, a message appears stating: Insufficient Funds. Calculate interest at 1% of the Starting Balance.

Any advice on how to start/approach this program, how to calculate the interest and how to pop up an error message would be greatly appreciated. Again we use Ruby.