The more effective way to do the step you mentioned above for "includes/templates/your-template/common/html_header.php" is to create a new file called:
includes/templates/YOURTEMPLATE/jscript/jscript_google_analytics.php
... and put the code you suggested above into that file instead.
This will make upgrading Zen Cart easier because it won't have touched the html_header.php core file.



