QUOTE – Simplicity

You’re not going to need to handle N kinds of book loan, you’re going to handle at most two, so don’t write some complicated code to handle the general case. You’re not going to need three classes, one interface and two event types for your “please wait” animation because there’s only ever going to be one and it’s always going to be while printing. Just write a function with a callback and release – the simpler it is, the quicker we can write it today and the more easily we can modify it tomorrow.

- coderoom