[php] How to place two forms on the same page?

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

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

so, I need something like:

if (!empty($_POST_01))...  // regForm
  and 
if (!empty($_POST_02))...  //loginForm

Also how to prevent executing first form if the second is busy, and vice versa (user clicks on both)
My idea is to create a simple variable on starting process, for example $x = 1 and at the end of process $x = 0, so:

if ((!empty($_POST_01)) And $x = 0)...

Probably, there is a better way.

You can use this easiest method.

<form action="validator.php" method="post" id="form1">_x000D_
    <input type="text" name="user">_x000D_
    <input type="password" name="password">_x000D_
    <input type="submit" value="submit" form="form1">_x000D_
</form>_x000D_
_x000D_
<br />_x000D_
_x000D_
<form action="validator.php" method="post" id="form2">_x000D_
    <input type="text" name="user">_x000D_
    <input type="password" name="password">_x000D_
    <input type="submit" value="submit" form="form2">_x000D_
</form>

Here are two form with two submit button:

<form method="post" action="page.php">
  <input type="submit" name="btnPostMe1" value="Confirm"/>
</form>

<form method="post" action="page.php">
  <input type="submit" name="btnPostMe2" value="Confirm"/>
</form>

And here is your PHP code:

if (isset($_POST['btnPostMe1'])) { //your code 1 }
if (isset($_POST['btnPostMe2'])) { //your code 2 }

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
}

Well you can have each form go to to a different page. (which is preferable)

Or have a different value for the a certain input and base posts on that:

switch($_POST['submit']) {
    case 'login': 
    //...
    break;
    case 'register':
    //...
    break;
}

Give the submit buttons for both forms different names and use PHP to check which button has submitted data.

Form one button - btn1 Form two button -btn2

PHP Code:

if($_POST['btn1']){
    //Login
}elseif($_POST['btn2']){
    //Register
}