Help please: Unable to get $_POST["variable"]; to work in a form.

I am going through the introductory tutorial on http://www.php.net/ and am stuck on this page: http://www.php.net/manual/en/tutorial.forms.php I have been able to get all of the examples up to this point to work. The form is simple: it asks for a text "name", a text "age" and has a submit button. The information is submitted to action.php. Action.php contains this code: Hi <?php echo $_POST["name"]; ?>. You are <?php echo $_POST["age"]; ?> years old. I saved action.php as a text file with only the information above. When I enter JoeBob into the name field and 27 into the age field, I get this for output: Hi Notice: Undefined index: name in c:\inetpub\wwwroot\action.php on line 1 . You are Notice: Undefined index: age in c:\inetpub\wwwroot\action.php on line 2 years old. What can I do to remedy this?