// Define private variable for maxFontSize.

public var _maxFontSize:Number = 15;

// Define public getter method, mark the property

// as usable for the source of data binding,

// and specify the name of the binding event.

[Bindable("maxFontSizeChanged")]

public function get maxFontSize():Number {

return _maxFontSize;

}

// Define public setter method.

public function set maxFontSize(value:Number):void {

if (value <= 30) {

_maxFontSize = value;

} else _maxFontSize = 30;

// Dispatch the event to trigger data binding.

dispatchEvent(new Event("maxFontSizeChanged"));

}