public boolean existeUser (String Nick) {

        //verificar logueo 
  String nombre="";
    boolean flag =false;
    
        try {
            String queryString = "Select nick from Usuarios where nick = ?";
            connection = getConnection();
            ptmt = connection.prepareStatement(queryString);
            ptmt.setString(1, Nick);
            resultSet = ptmt.executeQuery();
            if (resultSet.next()) {
             
              flag =true;

            }
            System.out.println("Data Recovery Successfully");
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (ptmt != null) {
                    ptmt.close();
                }
                if (connection != null) {
                    connection.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            } catch (Exception e) {
                e.printStackTrace();
            }

        }

        
        return flag;
        
    }