mixed up POST values in Perl script - forms

Question

I need to send POST values to server url, and I'm using this code:
$ogone_ua = new LWP::UserAgent;
$ogone_response = $ogone_ua->post("http://server.url/", {
'ACCEPTURL' => 'http://server.url2',
'AMOUNT' => '1000',
'CURRENCY' => 'USD',
'LANGUAGE' => 'en_US',
'ORDERID' => '20130105220939',
'PSPID' => 'vukasin',
'SHASIGN' => '6AEE128943C7C896A6449FF7C2CE702222995B7F'
} );
but server receives:
POST / HTTP/1.1
TE: deflate,gzip;q=0.3
Connection: TE, close
Host: athlon.herrpan.com:2389
User-Agent: SSL-AirKiosk/1.0
Content-Length: 206
Content-Type: application/x-www-form-urlencoded
LANGUAGE=en_US&ACCEPTURL=http%3A%2F%2Fserver.url2&SHASIGN=6AEE128943C7C896A6449FF7C2CE702222995B7F&CURRENCY=USD&AMOUNT=1000&PSPID=vukasin&ORDERID=20130105220939
Why it is not in order? The bank API needs POST values to be sorted, just like in code.

Answer 1

Hashes don't have an inherent order, so the order is lost before ->post is even called. However, POST (to which ->post passes its args) also accepts an array reference.
->post("http://server.url/", [
ACCEPTURL => 'http://server.url2',
AMOUNT => '1000',
CURRENCY => 'USD',
LANGUAGE => 'en_US',
ORDERID => '20130105220939',
PSPID => 'vukasin',
SHASIGN => '6AEE128943C7C896A6449FF7C2CE702222995B7F',
]);