How to place two forms on the same page?

Question

I want to place both register and login form on the same page.
They both starts with:

if (!empty($_POST)) ... 

so, I need something l

Answer 1

Hope this will help you. Assumed that login form has: username and password inputs.

if(isset($_POST['username']) && trim($_POST['username']) != "" && isset($_POST['password']) && trim($_POST['password']) != ""){
//login
} else {
//register
}