I have recently taken up .net game programming and have been through a few tutorials but have now decided on a project of my own. I've drawn up a plan for my project but cant figure out the best way to check for a win.

Game Background
Basically each level will have a certain amount of random coloured blocks at the top of the screen. These blocks are created in a class I have created which has four parameters (Size, Location, Colour1, Colour2).

Each block on the screen is stored in a two dimensional array of my block class.

The user will control a shooter at the bottom of the screen which will generate a random coloured block. When the block is shot and stops i need to test the two blocks above and two blocks to the left and right to see if they are the same colour. Then if they are this will be a win and the blocks will disappear.

The problem i have is how to check for the win.

Any help will be appreciated