no resource on fopen for url

[kireol]

why does this code produce a no resource error? I pasted the non encoded URL into a browser and it worked fine.

URL = http://testing.shippingapis.com/ShippingAPITest.dll?API=ZipCodeLookup&XML=<ZipCodeLookupRequest USERID=\"571DIREC3015\" PASSWORD=\"\"><Address ID=\"0\"><Address1> </Address1><Address2>6406 Ivy Lane</Address2><City>Greenbelt</City><State>MD</State></Address></ZipCodeLookupRequest>

code =

   1.
      <?php
   2.
              $LOGINURL = "API=ZipCodeLookup&XML=<ZipCodeLookupRequest USERID=\"571DIREC3015\" PASSWORD=\"\"><Address ID=\"0\"><Address1> </Address1><Address2>6406 Ivy Lane</Address2><City>Greenbelt</City><State>MD</State></Address></ZipCodeLookupRequest>";
   3.
              $LOGINURL = urlencode($LOGINURL);
   4.
              $LOGINURL = "http://testing.shippingapis.com/ShippingAPITest.dll?" . $LOGINURL;
   5.
              $zipres = fopen ($LOGINURL, "r");
   6.
              while(!feof($zipres))
   7.
              {
   8.
                      $zippage .= fread($zipres,8192);
   9.
              }
  10.
              print $zippage;
  11.
      ?>