Customizing Chapter

[Teddy Surya Gunawan]

Hi,

I want to change the appearance of Chapter. I am using report class to
write my thesis. So, how can I customize lyx/latex from :

Chapter 1
Introduction

to :

                              Chapter 1
                            Introduction
--------------------------------------------------------------------------

(centered and got line below, the line should be the same length with the 
header line)

Do I have to make something like \renewcommand{chapter} ?

Any suggestions would be appreciated.

TIA,

teddy