Can you help me to convert the following Python code to PHP - Many Thanks

import urllib
import urllib2
from xml.dom import minidom

user="YourUserName"
password="YourPassword"

site='https://test.api.betfairgames.com/rest/v1/bet/order'
site=site+"?username="+user

xml_request1="""<postBetOrder
xmlns="https://api.betfairgames.com/rest/v1"
round="1" marketId="3829306" currency="GBP">
<betPlace>
<bidType>BACK</bidType>
<price>2.6</price>
<size>4</size>
<selectionId>658439</selectionId>
</betPlace>
</postBetOrder>"""

values = {'xmlRequest':xml_request}
data=urllib.urlencode(values)

req=urllib2.Request(site)
req.add_header('Content-Type', 'application/x-www-form-urlencoded')
req.add_header('gamexAPIAgent','maryBrown@AOL.com. myGames.4.0')
req.add_header('gamexAPIAgentInstance','0d69ee8290 ee2f9b336c1f060e3497a5')
req.add_header('gamexAPIPassword',password)
req.add_header('Keep-Alive','300')
req.add_header('Proxy-Connection','keep-alive')
req.add_header('Content-Type','application/x-www-form-urlencoded')
req.add_header('Content-Length',str(len(data)))
req.add_data(data)

xmlresult = urllib2.urlopen(req)
xmlparser = minidom.parse(xmlresult)

print xmlparser.toxml()