problem of my code

if (pictureBox34.Image ==  chess9.Properties.Resources.siyahsah2))
{
    f();
}

public void picarray()
{
    pic[0, 4] = pictureBox34;
}

public void f()
{
    int x = 3;
    mode = hold;
    int y = 3;
    for (int i = 1; i < x; i++)
    {
        for (int j = 1; j < y; j++)
        {
            pic[i, j] = pic[i + 1, j + 1];
            pic[i, j] = pic[i - 1, j - 1];
        }
    pic[i, j].Image = Image.FromFile("pic/siyahsah2.jpg");
}