Hi.. Doubt regarding Tiles in Struts 2

[Vijayan]

Hi.. i am migrating my Application from Struts 1.x to 2.0. but now am 
facing problem in Tiles.
now am getting the following error  Error configuring application 
listener of class org.apache.struts2.tiles.StrutsTilesListener
what i have to do for solving this problem.  and where to include the 
<dependency> (i mean in which file) ?
am facing this problem for past 2days. pls help me as soon as possible.
Thanks & Regards,
Vijayan.R