I am trying to set a value to an already string labeled radio button. I do not understand my mistake. : 
public class RoomListener implements ActionListener
	{
		public void actionPerformed(ActionEvent event)
		{
			double roomtype; 
			
			if (event.getSource() == room1)
				roomtype = 60;
			else if (event.getSource() == room2)
				roomtype = 75;
			else 
				roomtype = 100;
		}

	}


public class CostListener implements ActionListener
	{
		public void actionPerformed(ActionEvent event)
		{
			double NightLength, roomNumber, cost;
			String NightText = NumberOfNights.getText();
			String RoomText = NumberOfRooms.getText();
			
			NightLength = Double.parseDouble(NightText);
			roomNumber = Double.parseDouble(RoomText);
			
			RoomListener.actionPerformed(RoomType);
			cost = roomtype * NightLength * roomNumber;
			
			CostCalculation.setText(Double.toString(cost));
			NumberFormat fmt = NumberFormat.getNumberInstance();
			CostCalculation.setText(fmt.format(cost));
		}
	}