3x3 Magic Number Game
da Barry Gelston

1. User Interface
2. Processes
2.1. Summing
2.1.1. sum each row
2.1.1.1. store in row summation cells
2.1.2. sum each column
2.1.2.1. store in column summations cells
2.1.3. sum both diagonals
2.1.3.1. store in diagonal summation cells
2.2. Error Checking
2.2.1. Cell validity
2.2.1.1. Actions
2.2.1.1.1. Don't allow wrong entry
2.2.1.1.2. provide a brief message
2.2.1.2. Test
2.2.1.2.1. Test for numbers 1-9
2.2.1.3. Rules
2.2.1.3.1. numbers
2.2.1.3.2. between 1 and 9
2.2.2. Alerts
2.2.2.1. Duplicates
2.2.2.1.1. For every cell change test for duplicate in the other 8 cells
3. Visual Cells
3.1. 3x3 cells
3.1.1. Create 9 varialbe
3.1.2. show on board
3.2. Summation cells
3.2.1. Create 8 summing variables
3.2.1.1. each row
3.2.1.2. each column
3.2.1.3. each diagonal