No, this is not that hard to do. You would need to generate a unique number which you can do a few different ways. One way would be to use the following code:
// generate a random number between 1000000 + 99999999
$order_id= mt_rand(1000000,9999999);
// make sure this order_id doesn't exist as an order
$sql = "select * from orders where order_id = '$order_id'";
// set up a loop that checks the order_id until it gets one that hasn't been used.
You could also set up your order_id field in your database as AUTO_INCREMENT so that it will assign a unique number to every order added to your table.
It sounds like this is going to be a fairly simple form. No credit card processing involved, right? Basically you want to take the form output, add it to your database with a unique order id and then email the results to someone. That shouldn't be that hard to do.
