getting return data from url - php

Question

I'm trying to submit user information to a URL using GET, and then get the errors (if there any) and use them to tell the customer what went wrong. So, currently I have a form that submits this customer info into an iframe (so the page is not redirected and I can see the response from my shopping cart software). when the info is submitted, this is the response I get from the shopping cart server:
errorFound=1&responseCode=329&...etc.
I need to get this response code, and was wondering what the most simple way would be to do it. Once I get it I can tell the customer what the problem is... Should I use java to read the
data in the iframe once it loads? or can I use something like Fopen to open the URL and get the return data (can't enable fopen on my server though, but something like it?).

Answer 1

Java != javascript
A quick way to do it:
$errorcodes = array("329" => "Wrong blabla");
if( isset( $_GET['errorFound'] ) && isset( $_GET['responseCode'] ) ){
$errorNr = (int) $_GET['responseCode'];
$error = getErrorFromDB();
//OR
//$error = isset( $erorCodes[ $errorNr ] )? $errorcodes[ $errorNr] : false;
if( $error !== false){
exit( "<script type='text/javascript'>
alert( '".htmlspecialchars($error)."' )
</script>");
}
}
function getError( $code )
{
$code = (int) $code;
$db = getYourPdoInstance();
$q = $db->prepare("SELECT `message` FROM `errorCodes` WHERE `errorCode` = ?");
$q->execute( array( $code) );
$return = $q->fetch(2);
return isset($return['message'])?$return['message']:false;
}