input: Write a function to determine if it is possible to create a HTML page that displays a table of contents from the data stored in a database. If it is possible return "Yes" else return "No". Assume that a database connection and relevant data are available.
  assert display_table_of_contents("connected")=="Yes"
  assert display_table_of_contents("not connected")=="No"
  assert display_table_of_contents("")=="No"
output: def display_table_of_contents(connection_status):
      if connection_status == "connected":
          return "Yes"
      else:
          return "No"