trying to use define in a loop to actually define but it;s not working

Hi

I'm trying to use define in a loop yet it keeps simply printing to my screen, rather than actuslly setting the define, any ideas what I'm doing wrong please.

I cant show the xml or full result as it's commercially confidential but here' s the idea

config.php page is actually the code attached. It gets the config.xml file and from that should set the defines for the whole application, this worked when I simply had the defines hard coded into the php page.

Now, it appears to write the output to the screen (which it should not) and it is in exactly the correct form but everything that then uses the defined bits doesn't work.

Any ideas please.

Here is a basic example of what it's outputting:

define( "_DEBUG", 0 );      
define( "_GLOBAL_TITLE", "test1" );      
define( "_BASE_URL", "test2" );      
define( "_CLIENT_SERVICE_ID", "test3" );      
define( "_ORIGINATOR", "test4" );      
define( "_CURRENCY", "test5" );      
define( "_USER_DEFINED_REQUEST_FIELD_1", "test6" );      
define( "_USER_DEFINED_REQUEST_FIELD_2", "test7" );      
define( "_USE_3D_SECURE", 1 );      
define( "_ACS_NOT_AVAILABLE", "test8" );      
define( "_CARD_TYPE_MANDATORY", 1 );      
define( "_CLEAR_SESSIONS_ON_SUCCESS", 0 );      
define( "_EMAIL_FROM", "test9" );      
define( "_EMAIL_COPY", "test10" );      
define( "_EMAIL_SUBJECT_PREFIX", "test11" );      
define( "_TRANSACTION_LOG", "test12" );      
define( "_TRANSACTION_LOG_SEPERATOR", "|" );      
define( "_PAYMENT_LOG", "test13" );      
define( "_PAYMENT_LOG_SEPERATOR", "," );      Start Free Trial

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<?php 
require_once("includes/classes/logger.class.php");
$xml = simplexml_load_file('config.xml');
foreach($xml as $name => $value) {	
  if ($value == "0" or $value == "1") {$quote = '"';} else {$quote = '';}
	?>
	define( "<?php echo "_".strtoupper($name); ?>", <?php echo $quote; ?><?php echo $value; ?><?php echo $quote; ?> );	
	<?php
	}
?>