To retrieve data as xml without header using SIMPLEXMLELEMENT in php -

i trying output this-

<start> <sub1> <one>sam</one> </sub1> </start> 

for tried code-

<?php   include('db.php');  $xml = new simplexmlelement();  $abc = $xml->addchild('start'); $s = $abc->addchild('sub1'); $s->addchild('one','sam');  echo $xml->asxml();  ?> 

but not giving me output.instead giving me error. error follows- fatal error: uncaught exception 'exception' message 'simplexmlelement::__construct() expects @ least 1 parameter, 0 given' in d:\xamppnew\htdocs\_acct\trialxml.php:5 stack trace: #0 d:\xamppnew\htdocs\_acct\trialxml.php(5): simplexmlelement->__construct() #1 {main} thrown in d:\xamppnew\htdocs\_acct\trialxml.php on line 5

can guide me how retrieve xml without header using simplexmlelement in php or please let me know went wrong. in advance.

simplexml can not work empty document. need load document document element.

$start = new simplexmlelement('<start/>'); $s = $start->addchild('sub1'); $s->addchild('one','sam');  echo $xml->asxml();