functions.php

//Google Experiment Code
function google_experiment_code() {
  
  // NOTE replace 123 with your page ID
  if( is_page(123) ) {
    ?>
    <!-- Google Analytics Content Experiment code -->
    <script>function utmx_section(){}function utmx(){}(function(){var
    k='30041124-5',d=document,l=d.location,c=d.cookie;
    if(l.search.indexOf('utm_expid='+k)>0)return;
    function f(n){if(c){var i=c.indexOf(n+'=');if(i>-1){var j=c.
    indexOf(';',i);return escape(c.substring(i+n.length+1,j<0?c.
    length:j))}}}var x=f('__utmx'),xx=f('__utmxx'),h=l.hash;d.write(
    '<sc'+'ript src="'+'http'+(l.protocol=='https:'?'s://ssl':
    '://www')+'.google-analytics.com/ga_exp.js?'+'utmxkey='+k+
    '&utmx='+(x?x:'')+'&utmxx='+(xx?xx:'')+'&utmxtime='+new Date().
    valueOf()+(h?'&utmxhash='+escape(h.substr(1)):'')+
    '" type="text/javascript" charset="utf-8"></sc'+'ript>')})();
    </script><script>utmx('url','A/B');</script>
    <!-- End of Google Analytics Content Experiment code -->
    <?php
    }
  }
add_action( 'wp_head','google_experiment_code', 5 );