telling the program that this is the first opening of page

[ms1990kl]

This is probably basic, but I want to tell my program that this is the first opening of the current session so that my program will load all my default values in my forms. 

After some inputs are submitted, I want the program to know that the session is no longer at the beginning.

Is there some session variable that is set upon opening of the session, then unset after inputs are submitted?

 

Thanks,

Mike

[RussellReal]

<?php
  session_start();
  if (!isset($_SESSION['first'])) {
    // load defaults here
    $_SESSION['first'] = 1;
  }
?>