是否可以将Google Analytics代码放在外部JS文件中？

var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "https://www.");
document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));

try 
{
    var pageTracker = _gat._getTracker("UA-XXXXXXX-1");
    pageTracker._trackPageview();
}
catch(err) {}
var gaJsHost = (("https:" == document.location.