<?php

$xml = "<smses>
<sms body='something' type='1' address='1234'/>
<sms body='something' type='2' address='12345'/>
<sms body='something' type='2' address='1234'/>
</smses>";

$doc = new DOMDocument();
$doc->loadXML($xml);

$path = new Domxpath($doc);

$num = 1234;

$result = $path->query("//smses/sms[@address='$num']");

foreach($result as $res)
{
    echo "<div id='sms' class='" . $res->getAttribute("type") . "'>".$res->getAttribute("body").'</div><br/><br/>';
}

<div id='sms' class='1'>something</div><br/><br/><div id='sms' class='2'>something</div><br/><br/>