title: Send $_GET or $_POST in functions
body: <p>I want get parameters from a form and send <code>caption</code> parameter to a function to change character encoding! </p>
  
  <p><strong>PHP Code</strong></p>
  
  <pre><code>if (isset($_GET['username']) &amp;&amp; isset($_GET['password'])){
      $username = $_GET['username'];
      $password = $_GET['password'];
      $captione  = $_GET['caption'];
      echo $captione.'&lt;br&gt;';
      echo convert_u($captione);
  }else{
      loginForm();
  }
  
  function convert_u($cap){
      $cap = str_replace('ض','"\u0636"',$cap);
      $cap = str_replace('ص','"\u0635"',$cap);
      $cap = str_replace('ث','"\u062b"',$cap);
      return $cap;
  }
  </code></pre>
  
  <p>The form <code>enctype</code> is <code>multipart/form-data</code>.</p>
  
  <p>When I type <code>convert_u('حامد');</code> or <code>convert_u($parameter);</code> this works.</p>
  
  <p>But when send parameter that receive from <code>$_GET</code> and <code>$_POST</code> it doesn't work!!</p>