public void changeBackgroundImage(String str) {
		if (isRemote())
			throw new RuntimeException("Background image of a remote page cannot be changed.");
		if (str == null) {
			if (getBackgroundImage() != null)
				setBackgroundImage(null);
		} else {
			if (str.equals("null") || str.trim().length() == 0) {
				if (getBackgroundImage() != null)
					setBackgroundImage(null);
			} else {
				ImageIcon icon = null;
				if (!FileUtilities.isRemote(str)) {
					icon = new ImageIcon(Toolkit.getDefaultToolkit().createImage(str));
				} else {
					try {
						icon = new ImageIcon(new URL(str));
					} catch (MalformedURLException mfe) {
						mfe.printStackTrace();
					}
				}
				if (icon != null) {
					icon.setDescription(str);
					setBackgroundImage(icon);
				}
			}
		}
	}