private void button3_Click(object sender, EventArgs e) { if (this.InvokeRequired) { dbutton3_Click d = new dbutton3_Click(button3_Click); object[] args = { sender, e }; this.Invoke(d, args); } else { if (AcceptedEmulator != null) { if (AcceptedEmulator.IsConnected) { AcceptedEmulator.Send("STEP\n"); } } } }