headers already sent Warning when using Google Anayltics Experiments code

[satsumo]

I am getting the error WARNING, headers already sent, for some reason it says the output started at the end of the google analytics tracking code for google experiments I had,the full file of that file is this\[code\]<!-- Google Analytics Content Experiment code --><script>function utmx_section(){}function utmx(){}(function(){vark='62393235-4',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 -->\[/code\]why would I be getting this error?