template hook

[yakoub 2]

hi i read about the The Bugzilla Extension Mechanism 
<http://www.bugzilla.org/docs/3.2/en/html/cust-hooks.html>
but i couldn't get it to work

i tried extending "template/en/default/bug/create/create.html.tmpl "
using hook [% Hook.process("end") %] just before the footer line
i created 
"extensions/myext/template/en/default/bug/create/create-end.html.tmpl" 
and wrote "hhhhhhh" in it
but when reloading the "open bug" page i didn't see "hhhhh" before the 
footer , so how should i do this ?
also what is the use of the template/en/extension/ directory ?