How to parse a value from an XML response which I got as a soap API response in PHP

I got an XML response as

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://ift.tt/sVJIaE" xmlns:ns1="http://api.*********.in">
   <SOAP-ENV:Body>
      <ns1:LoginResponse>
         <return>
            <SessionID>3AC46E3F62</SessionID>
            <ResponseCode>0</ResponseCode>
            <ResponseMessage>Successful</ResponseMessage>
         </return>
      </ns1:LoginResponse>
   </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

How can I parse the SessionID and ResponseCode from this xml using PHP.Im unable to do this.Please suggest some methods to do this.