public void setSelectedShowLayerCheckbox(int num)
	{
		switch (num)
		{
			case 0:
				this.showForeground.setSelected(!this.showForeground.isSelected());
			break;
			case 1:
				this.showMiddleground.setSelected(!this.showMiddleground.isSelected());
			break;
			case 2:
				this.showBackground.setSelected(!this.showBackground.isSelected());
			break;

			default:
			break;
		}
	}