public MemoryGrid(int gridSize){
		if (gridSize % 2 == 0) 
			size = gridSize;
		else{
			System.out.println("Grid Size Error: Grid size has to be even");
			System.exit(1);
		}
		numImage=gridSize;
		currentFlipped=new ArrayList<Integer>();
		for(int i=1; i<((size/2)+1); i++){
			MemoryCard temp  = new MemoryCard(i);
			MemoryCard temp2 = new MemoryCard(i);
			memGrid.add(temp);
			memGrid.add(temp2);
		}   

	}