Passing variables between pages

Briefly,

I have created a form, with a text box on it, in php on one page. The user will enter a search term, and the entered info will be passed to another page which will receive the info, then run a SQL query based on the text.

Question. How do I complete the <form action=”xxx.php” method=”post”> string so that it goes to another WP page, versus going to a static page. Perhaps the static page would be better, and that is what I am looking to find out.

Thanks