private void openDialog(){
        JFileChooser fileOpen = new JFileChooser("./");
        FileNameExtensionFilter filter = new FileNameExtensionFilter(
                "Algorythm workspace files .wks", "wks");
        fileOpen.setFileFilter(filter);
        int ret = fileOpen.showDialog(null, "Open file");
        if (ret == JFileChooser.APPROVE_OPTION) {
            openingFile = fileOpen.getSelectedFile();
            if(openWorkspace(openingFile))
                JOptionPane.showMessageDialog(this, "File open!", "Open file",JOptionPane.INFORMATION_MESSAGE);
            else
                JOptionPane.showMessageDialog(this, "Open filed!", "Open file",JOptionPane.ERROR_MESSAGE);

        }
    }