(button label fn) -> button?
  label: string?
  fn: procedure?

Creates a button with the given label and function that is called when the button is pressed.

(on-keydown! fn) -> void?
  fn: procedure?

Calls fn whenever a key is pressed while the page is focused. fn takes a single argument, the key pressed by the user as a string.

(tag name c) -> element?
  name: string?
  c: any

Creates an HTML element with the given name and children.

(tag-set-children! elt c) -> element?
  elt: an HTML element
  c: an HTML element or string

Sets elt's children to be c1, c2, ..

(text-area id) -> text-area?
  id: string?

Creates a text area with the given id.

(text-area-get text-area) -> string?
  text-area: text-area?

Returns the text in the given text area.