private void pictureBox1_Click(object sender, EventArgs e)
        {
            FrmMusteriler yeni = new FrmMusteriler();

            yeni.Show();
            this.Hide();
        }
        private void müşteriListesiToolStripMenuItem_Click(object sender, EventArgs e)
        {
            FrmMusteriler yeni = new FrmMusteriler();

            yeni.Show();
            this.Hide();
        }