protected String checkFolder(String folderPath) {
		File dir = new File(folderPath);
		
		if (!dir.exists()) {
			return("The music folder '"+folderPath+"' does not exist.");
		} else if (!dir.isDirectory()) {
			return("The music folder '"+folderPath+"' must be a directory.");
		} else if (!dir.canRead()) {
			return("The music folder '"+folderPath+"' can't be read. Check directory permissions");
		}
		
		return "";
	}