public void pressedEncrypt() {
		String imgPath = txtImage.getText();
		String filePath = txtFile.getText();

		if (imgPath.isEmpty() || filePath.isEmpty()) {
			displayError("Error", "Choose image and file!");
			return;
		}

		String imageSuffix = imgPath.substring(imgPath.lastIndexOf('.'), imgPath.length());
		if (!(imageSuffix.equalsIgnoreCase(".jpg") || imageSuffix.equalsIgnoreCase(".png")
				|| imageSuffix.equalsIgnoreCase(".gif") || imageSuffix.equalsIgnoreCase(".jpeg"))) {
			displayError("Error", "Only .png,.jpg and .gif files are supported!");
			return;
		}
		
		// Optional!
		// TODO check max file size
		// if too big = error
		// {
		// displayError("Error","File is too big for image maximume size = ??");
		// return;
		// }
		// where to save image
		
		File f = askForTargetFile();

		if (f == null) {
			displayError("Error", "Could not save file");
		}
		try {
			Steganography.encrypt(new File(filePath), new File(imgPath), f);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}