how to create a javascript Extension using jquery

how to create a javascript Extension using jquery


hi , i was trying to replace my javascript statements with jquery
statements by including the jquery file in *.xul file.
the xul file line is as under:
<script type="application/x-javascript" src="chrome://extensionname/
content/jquery-1.2.6.min.js""/>
and i am trying to access the "$"/ jquery fucntions in the other js
file of my plugin. but its not working.
plz help.