Graham TECRIDIBLE you could either add the code directly into the twig template for the blog post or use a xtscript to detect __xtblog_entry variable and only include the script then

<!--parser:xtscript--> get __xtblog_entry if $__xtblog_entry PRINT SCRIPT HERE endif <!--/parser:xtscript-->

If your script code uses brackets you may need to break them on to separate print lines
in the twig you would add the javascript directly in the {% elseif view == 'entry' %} area