E-commerce google analytic missed some order

[Bunty Singh]

hi my project is in opencart and i applied google analytic. some time it miss order in Google transaction.

Any idea

my code is below

////////////////////

<script>

var _gaq = _gaq || [];

_gaq.push(['_setAccount', 'XXXXXXX']);

_gaq.push(['_trackPageview']);

_gaq.push(['_addTrans',

   "<?php echo $order_id;?>",           // transaction ID - required

   "<?php echo $store_name;?>", // affiliation or store name

   "<?php echo $order_total;?>",          // total - required

   '0.00',           // tax

   "<?php echo $shipping_price;?>",          // shipping

   "<?php echo $payment_city;?>",       // city

   "<?php echo $payment_zone;?>",     // state or province

   "<?php echo $payment_country;?>"             // country

]);

<?php foreach ($product_data as $product) { ?>

_gaq.push(['_addItem',

   "<?php echo $order_id;?>",           // transaction ID - necessary to associate item with transaction

   '<?php echo $product["model"]; ?>',           // SKU/code - required

   '<?php echo $product["name"]; ?>',        // product name

   '<?php echo $product["category_name"]; ?>',   // category or variation

   '<?php echo $product["price"]; ?>',          // unit price - required

   '<?php echo $product["quantity"]; ?>'               // quantity - required

]);

<?php } ?>

_gaq.push(['_trackTrans']);

 (function() {

    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;

    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';

    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);

  })();

</script>

//////////////////

Thanks