I haven't done any xml projects, so I'm not quite sure what to do with this data...

I'm using curl to make a request to salesforce, and they give me back a response that I need to parse. I want to use simplexml. Here's part of the response:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns="urn:partner.soap.sforce.com" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<soapenv:Body>
<loginResponse>
<result>
<metadataServerUrl>
https://na6-api.salesforce.com/services/Soap/m/18.0/
</metadataServerUrl>
<passwordExpired>
false
</passwordExpired>
<sandbox>
false
</sandbox>
<serverUrl>
https://na6-api.salesforce.com/services/Soap/u/18.0/
</serverUrl>
<sessionId>
!AQ4AQLtDIqY.
</sessionId>
<userId>

</userId>
<userInfo>
<accessibilityMode>
false
</accessibilityMode>
<currencySymbol>
$
</currencySymbol>
<orgDefaultCurrencyIsoCode>
USD
</orgDefaultCurrencyIsoCode>
<orgDisallowHtmlAttachments>
false
</orgDisallowHtmlAttachments>
<orgHasPersonAccounts>
false
</orgHasPersonAccounts>
<organizationId>

</organizationId>
<organizationMultiCurrency>
false
</organizationMultiCurrency>
<organizationName>
Ox 
</organizationName>
<profileId>
sdfgsdfg
</profileId>
<roleId>
sdfgsdfg
</roleId>
<userDefaultCurrencyIsoCode xsi:nil="true"/>
<userEmail>
###@gmail.com
</userEmail>
<userFullName>
### ###
</userFullName>
<userId>
asdfasdf
</userId>
<userLanguage>
en_US
</userLanguage>
<userLocale>
en_US
</userLocale>
<userName>
[email protected]
</userName>
<userTimeZone>
America/Chicago
</userTimeZone>
<userType>
Standard
</userType>
<userUiSkin>
Theme3
</userUiSkin>
</userInfo>
</result>
</loginResponse>
</soapenv:Body>
</soapenv:Envelope>

Anyway, I expected to feed that stuff (we'll call it data) into

$results = simplexml_load_string($data);
var_dump($results);

And that would give me all the data back... and then to access specific parts, it would be $results->body->loginResponse->blah->blah...

But It's not giving me that, it's not really giving me anything back, just an empty simple xml object...

So one website made me think I might need an XSLT to read this correctly.
Or something else made me think it's because I don't have at the top.

Help!