[Tugindia] Centering a Section title

[David Owen]

Hi, Everyone,
Thanks for the help. I have two more little problems:
1)   I have tried to center on a page,  say,  the title "Introduction" by
using
\centerline{\section{Introduction}}
but it does not work. I am using Winedt and it gives the message
"Something's wrong. Perhaps a missing \item".
If I use
\centerline{  \bf{ Introduction} }
this does not give me what I want.
Can someone tell me what I am doing wrong?

2) Can someone tell me how to leave a space of say, 3.5cm, at the top of the
first page of a document but leave a margin of 4cm on all other pages?
Thanks again for everything.
D.O.