PHP Code:
<object
type="video/avi"
data="<?php echo $_POST['formInputName']; ?>"
width="100%"
height="100%">
$_POST[''] is a PHP command that grabs the data from your submitted form and turns it into a variable. Although server side scripting is usually used to retrieve form data, you could also use a client side language (e.g. Javascript) if you are just inserting the data into your HTML and not using it anywhere on the server side (e.g. submitting it to a database).