PHP5 - Pass variable to another *.php file..

I have a basic question.

I have a html submit page. After clicking the submit button, the input variables are passed (using <form action="1.php" method="post">) to 1.php. Then, the 1.php does some pattern matching works. Now I want to pass the output values of 1.php to 2.php. How do I do it? Any example on the web already?

Because 2.php will be used/called by other files as well to access MySQL database, I do not want to combine 1 and 2 together. Thanks a lot.

yes, about 13,700,000 of them