public File getFile() {
		JFileChooser fc = new JFileChooser();
		int result = fc.showOpenDialog(new JFrame());
		File sendfile;
		if (result == JFileChooser.APPROVE_OPTION) {
			sendfile = fc.getSelectedFile();
			filename = sendfile.getAbsolutePath();
			filesize = (int)sendfile.length();
			jLabel1.setText("傳送檔案" + filename);
			jLabel2.setText("大小: "+filesize+" bytes");
			jLabel3.setText("等待對方接收...");
			return sendfile;
		}
		else return null;
	}