moving jquery

moving jquery

i am new to html and wondering why i cant move jquery to a sub folder? i have the following...
root
index.html
-lib
jquery.js
-img

however when i use 
  1. <script type="text/javascript" src="lib/jquery.js"></script>
it wont work :( i have tried without  type="text/javascript" aswell

hope someone can shed some light :)