Looks like you're mixed up on a few points, but the main one I see is it looks like you're trying to make the class name include the entire package. A working example of what I think you want would be:
package controls
// ^^^^^^^^ The controls package is defined here, not when providing the
// class name like in your example.
{
import flash.display.SimpleButton;
// ^^^^^^^^^^^^^ In ActionScript 3, SimpleButton is in the
// flash.display package, and needs to be imported with an
// import statement above the class definition.
public class Button extends SimpleButton
// ^^^^^^ We only use the class name here. You can do the fully
// qualified class name for the extended class, but the
// import statement is cleaner and makes that unnecessary
// except for in uncommon circumstances.
{
private var enabled:Boolean = false;
private var borderW:int = 1;
public function Button()
{
// Constructors must be public.
}
public function draw()
{
//
}
}
}
And your other class:
package
{
import controls.Button;
// ^^^^^^^^^^^^^^^ Need to import your above Button class.
public class IF12345
{
public var a0:Button;
}
}