Implement A Default Onload Handler ?

Our project has thousands of web pages.

We have certain default chores we would like to occur as part of the
onload handling for all of these pages.

Rather than modify every page to say

window.attachEvent("onload",defaultChores);

is there some neat way to perhaps tap into the page-loading process so
that the above attachEvent call gets performed implicitly ?

Perhaps this involves some sort of server intervention. That is a
possibility for us, as we have access to the server as well (it's
typically a tomcat server), although admittedly if this is the only way
to do this, then this discussion should quickly migrate out of the
javascript newsgroup and into some sort of web server one.