XML : How do I use PHP to write multiple nodes of the same name to an XML file?

I'm trying to use my PHP to take input from a form and write it to an XML file. It works fine for the unique fields, but there's one field that can be inputted 4 times.

When more than one is entered, only the last one is written to the XML file.

My PHP:

  <?php          if(isset($_REQUEST['ok'])){              $xml = new DOMDocument("1.0","UTF-8");              $xml->load("../Players.xml");                $rootTag = $xml->getElementsByTagName("site")->item(0);                $entryTag = $xml->createElement("entry");                $nameTag = $xml->createElement("name",$_REQUEST['name']);              $countryTag = $xml->createElement("country",$_REQUEST['country']);              $memTag = $xml->createElement("mem",$_REQUEST['mem']);                $entryTag->appendChild($nameTag);              $entryTag->appendChild($countryTag);              $entryTag->appendChild($memTag);                $rootTag->appendChild($entryTag);              $xml->save("../Players.xml");           }  ?>    

Form:

          <form action="index.php" method="post">              <input type="text" name="name"/>              <input type="text" name="country"/>              <input type="text" name="mem"/>              <input type="text" name="mem"/>              <input type="text" name="mem"/>              <input type="text" name="mem"/>              <input type="submit" name="ok"/>          </form>