Arrow key navigation between TextBoxes in UserControl elements in a FlowLayoutPanel

The attached application has a FlowLayoutPanel control on the Form.
The FlowLayoutPanel contains UserControls of the same type.
The UserControl class contains four TextBox controls inside.

This application shows how to have arrow key navigation in this scenario.
All arrow key have been used (Up, Left, Button and Right).

Application written in C# in MS Visual Studio 2005.

Important notice:
This implementation is not the VWG official recommendation for this use.
The reason for that is that it requires registration to the KeyDown event on all relevant TextBoxes. This would cause a great many roundtrips - one for every key press.
I intend to soon remake this application in a way that some of the logic would move to client-side by creating a CustomTextBox that would have a new ArrowKeyPressed event that would be raised by client-side logic - checking what key was pressed on the TextBox.

This would save a lot of unnecessary roundtrips.

Please watch this article for updates...

Note: Codes are submitted as a .zip file to shorten your download time. After downloading it, you will need a program like Winzip to decompress it.

Terms of Agreement:
By using this code, you agree to the following terms...

1. You may use this code in your own programs (and may compile it into a program and distribute it in compiled format for languages that allow it) freely and with no charge.
2. You MAY NOT redistribute this code (for example to a web site) without written permission from the original author. Failure to do so is a violation of copyright laws.
3. You may link to this code from another website, but ONLY if it is not wrapped in a frame.
4. You will abide by any additional copyright restrictions which the author may have placed in the code or code's description.