I solved it with main form Resize event... and playing with groupbox Top and Height properties. Thanks anyways.... :)

;)

Thanks Henry Minute, i just googled ypur string and found this Custom Configuration Sections for Lazy Coders[^] Exactly what i was searching... :)

I have an other Thread t,and I can get the checkbox value from UI thread in Thread t. see follow source code. private void Form2\_Load(object sender, EventArgs e) { Thread t = new Thread(new ThreadStart(deal)); t.Name = "deal"; t.IsBackground = true; t.Start(); } void deal() { while (true) { System.Diagnostics.Debug.WriteLine(checkBox1.Checked); Thread.Sleep(1000); } }

And how can i compress a string... tryed to compress the original string but the reult is different. I´m confused... perhaps someone can help. Thanks in advance. ;)

You're welcome. The problem was that the TextBox uses the Environment.NewLine while the RichTextBox uses any of '\n' and '\r' too as line breaks. I didn't know that, thanks for the info. Eslam Afifi