Learning PHP - question about hidden form fields

Hey all! I sat down and started learning PHP today and ran into a bit of a spot. Hoped someone here could lead me in the right direction. I created a simple test form called form.php. I thought I had this strait in my mind when I created it, but obviously it didn't work. All I want to do is create a static value and pass it back to the page which then triggers a statement for the user to read. Problem I'm running into is that I can't seem to find a way to pass that variable correctly with all this being on a single file. I'd prefer to do this in a single file if possible. Any ideas? <html> <head> <title>Test Form</title> </head> <body> <?php if (defined('form_submitted')) { echo "<p>Thank you for submitting your trouble ticket. We have received your trouble ticket and will be in touch with you about it as soon as possible.</p>"; echo "<p>If you wish to submit another ticket, please use the form below.</p>"; } echo "<form action='form.php' method='post'>"; echo "<input type='hidden' name='preform_submitted' value='y'>"; echo "<input type='hidden' name='form_submitted' value='$preform_submitted'>"; echo "<table>"; echo "<tr><td>Last Name:</td><td><input name='lname' type='text'></td></tr>"; echo "<tr><td>First Name:</td><td><input name='fname' type='text'></td></tr>"; echo "<tr><td>Email Address:</td><td><input name='email_add' type='text'></td></tr>"; echo "<tr><td colspan=2>Trouble:</td></tr>"; echo "<tr><td colspan=2><textarea name='explan'></textarea></td></tr>"; echo "<tr><td><input type='submit'></td></tr>"; echo "</table>"; echo "</form>"; ?> </body> </html>