problem linking jquery keypad plugin to jsp page

problem linking jquery keypad plugin to jsp page

hi all
i have a unique problem with linking jquery keypad plugin with a jsp page in a project. i downloaded the keypad plugin from jquery site and put it in a library folder in my project. now when i try to link the js file from there, i get javascript error.

my jsp page is in folder1 under WebContent and my keypad.js is under folder2/common/jquery.keypad.js.

this folder2 is also under WebContent. i tried to check the link using firebug, its showing the path given is correct. but when i try to use the method in it, i get javascript error : "$.keypad is undefined" or "keypad() is not a function "

i can even open the js file from the link.  and strangely enough when i put the

jquery.keypad.js in folder1,
everything starts working.

this is the path which i use for folder2  :
<script type="text/javascript" src="../folder2/common/jquery.keypad.js"></script>

and this is the path which i use for folder1:
 <script type="text/javascript" src="/jquery.keypad.js"></script>

can anyone tell me what is going wrong here. i can't understand the path problem as i am using many other jquery libraries using the same path.