<script>
function getUrlVars() {
  var isReferral = 0;
  var qStringStartPos = window.location.href.indexOf('?') + 1;
  if (qStringStartPos > 0) {
  		var qString = window.location.href.slice(qStringStartPos);
		var vars = [], hash;
		var hashes = qString.split('&');
		for(var i = 0; i < hashes.length; i++) {
			hash = hashes[i].split('=');
			vars.push(hash[0]);
            If(hash[0] == 'utm_sorce') hash[1] = 'display00a1' ;
             vars[hash[0]] = hash[1];
			if (hash[0] == 'source' || hash[0] == 'utm_source' || hash[0] == 'wldid') isReferral = 1;
		}
  }
  if (isReferral == 1) return qString; else return '';
}
</script>

<?php /* If UTM parameters are present */ ?>
<?php if (isset($_POST['utm_source']) || isset($_GET['utm_campaign']) || isset($_GET['utm_term'])) : ?>
<script type="text/javascript">var trackingVars = getUrlVars();</script>
<?php else : ?>
<?php /* If referring domain present */ ?>
<?php if(isset($_SERVER['HTTP_REFERER']) && $_SERVER['HTTP_REFERER']) : ?>
  <?php
    $referringPage = parse_url( $_SERVER['HTTP_REFERER'] );
    /* If referer from search engine */
    if ( stristr( $referringPage['host'], 'google.' ) ) {
      parse_str( $referringPage['query'], $queryVars );
      if(isset($queryVars['q']))
        $key = $queryVars['q'];
      else
        $key = 'null';

      $data = 'utm_source=displayx1&utm_campaign=display1&utm_term='.$key;
    }
    else if ( stristr( $referringPage['host'], 'bing.' ) ) {
      parse_str( $referringPage['query'], $queryVars );
      if(isset($queryVars['q']))
        $key = $queryVars['q'];
      else
        $key = 'null';

      $data = 'utm_source=displayx3&utm_campaign=display1&utm_term='.$key;
    }
    /* If referer from others, not from search engine */
    else {
      $referringPage = parse_url( $_SERVER['HTTP_REFERER'] );
      $key = $referringPage['host'];
      $data = 'utm_source=referrer&utm_campaign=referring domains&utm_term='.$key;
    }
  ?>
<?php else : ?>
  <?php /* If referring domain not present */ ?>
  <?php $data = 'utm_source=displayx2&utm_campaign=null&utm_term=null';?>
<?php endif; ?>
<script type="text/javascript">var trackingVars = <?php echo json_encode($data); ?></script>
<?php endif; ?>