put this in the places on the pages you want to include the update:
Code:
<script language="JavaScript" src="/location/of/file.js"></script>
now create a javascript file with what you want in it.
file.js =
Code:
function writeStuff()
{
str = "Hello. Hello. Hello";
return str;
}
document.write.(writeStuff());
Note: Very, very cheesy solution, there.