How to write a class to return textbox control

[Domkiustletnstiskowe]

How do I write a class for something like thisExample: I have a \[code\]form\[/code\] that has a panel on it. That panel has an tabbed control. In that tabbed control there is a \[code\]textbox\[/code\]. If I pass the \[code\]form\[/code\] as the start control and