PHP Manual . ... Variables . ... When a form is submitted to a PHP script, any variables from that form will be automatically made available to the script by PHP. ... Simple form variable . form action="foo.php" method="post"> Name: <input type="text" name="username"><br> <input type="submit"> </form> . ... The experienced may note that the actual variable names sent by the browser contains a period rather than an underscore, but PHP converts the period to an underscore automatically. ...