radiogroup.go
func (c *RadioGroup) Selected() int {
	selected := -1

	for id, item := range c.items {
		if item.Selected() {
			selected = id
			break
		}
	}

	return selected
}
func (c *RadioGroup) Selected() int {
	selected := -1

	for id, item := range c.items {
		if item.Selected() {
			selected = id
			break
		}
	}

	return selected
}
// Selected returns the number of currently selected radio
// button inside the group or -1 if no button is selected