connection was not closed current state is open

 public OleDbConnection conn;
  public OleDbDataAdapter da;
  public OleDbDataReader reader;
  public DataSet ds;
  public DataTable dt;
  public OleDbCommand cmd;
 
  try
           {
 
               cmd = new OleDbCommand("UPDATE tbl_user_login SET password='" + txt_password.Text + "' WHERE username='" + txt_username.Text + "' ", conn);
               if(conn.State != ConnectionState.Open)
                {
                conn.Open();
                }

               cmd.CommandType = CommandType.Text;
               OleDbDataAdapter da = new OleDbDataAdapter(cmd);
               cmd.CommandType = CommandType.Text;
               cmd.ExecuteNonQuery();
               MessageBox.Show("updated successfully");
           }
           catch (Exception ex)
           {
               MessageBox.Show((ex.ToString()));
           }
           finally
           {
               if(conn.State == ConnectionState.Open)
               {
                   conn.Close();
               }
           }