Dynamic Form

Hello, How i make dynamic form?

I have models: game, and part. Game can have many parts. Game and Part have "one -to -many" relationship.

I need to make a form which has a button like “add part” and every time click on the button “part” model’s create form is appended to “game” model’s create form. And then when click on the button like “submit game”, i need to validate all parts on the game form. The main things are that dynamically add part to game and validate all part when submit game form. How do i do this ? Help