public class Image
{
    public Image(int x, int y)
    {
        _theWorld = new Tile[x][y];

        for (int i = 0; i < x; i++)
        {
            for (int j = 0; j < y; j++)
                _theWorld[i][j] = null;
        }
    }

    public void placeTile (Tile theTile, int x, int y)
    {
        _theWorld[x][y] = theTile;
    }

    public Tile getTile (int x, int y)
    {
        return _theWorld[x][y];
    }

    private Tile[][] _theWorld;
}
@@ -284,32 +284,159 @@
 x, int y)%0A    %7B%0A
+        if (_theWorld%5Bx%5D%5By%5D != null)%0A            System.out.println(%22Warning: overwiting tile %3C %22+x+%22, %22+y+%22 %3E%22);%0A            %0A
         _theWorl

Update Image.java