Form Posting/Get doesn't work

Hi... I have a simple php page with a form on it but my bit which displays the result of the form doesn't work... This is what i have in my php page. Hi <?php echo $name; ?>. You are <?php echo $age; ?> years old. <form action="um.php" method="post"> Your name: <input type="text" name="name"> You age: <input type="text" name="age"> <input type="submit"> </form> It should display the name and age but doesn't.... I installed php as the instructions on php.net said and i am using apache.... It is like the values arent actually been posted even though if i change the method to get i can see them on the command line.... It is very strange! Any help would be much appreciated Stuart