private void btnOpen_Click(object sender, EventArgs e)
        {
            OpenFileDialog o = new OpenFileDialog();
            o.CheckFileExists = true;
            o.FileName = "overlay9_12";
            if (o.ShowDialog() != System.Windows.Forms.DialogResult.OK)
                return;

            ov = o.FileName;
            km = new KeyManager(ov, (int)numBaseAddress.Value, (int)numRAMadd.Value);

            o.Dispose();
            o = null;

            numKey.Enabled = true;
            numPage.Enabled = true;
            txtKey.Enabled = true;
            btnWrite.Enabled = true;

            numKey_ValueChanged(null, null);
        }
        private void numOveralyadd_ValueChanged(object sender, EventArgs e)
        {
            if (ov == null || ov == "")
                return;

            km = new KeyManager(ov, (int)numBaseAddress.Value, (int)numRAMadd.Value);
            numKey_ValueChanged(null, null);
        }