title: Check wheter $_POST is set with a self-defined function?
body: <p>I'm working on a function to check wheter a $_POST is set or not.</p>
  
  <p>The following works fine:</p>
  
  <pre><code>if (isset($_POST['einfo'])) {
      $einfo = $_POST['einfo'];
  } else {  $einfo = NULL; }
  </code></pre>
  
  <p>echo $einfo; </p>
  
  <p>And this is the function i'm trying to make: </p>
  
  <pre><code>  function  ifset($check) {
         if (isset($_POST['$check'])) {
       $check = $_POST['$check'];
      } else {  $check = NULL; }
        return $check;
  }
  
  $einfo = ifset('einfo');
  
  echo $einfo; 
  </code></pre>
  
  <p>But i get no output.</p>