Center something

Hello

I’m trying to center the top banner on my site.

But I’m unable to do so.

Here’s the code I’m using now:

#Topad {
    position: absolute;
    top: 7em;
}

I’ve tried all these lines:

#Topad {margin-left: auto;
margin-right: auto;}

In the HTML too:

<div align=”center”>…</div>

<center>…</center>

My site: http://geimaku.com

Nothing seems to work. Help, please.

Thanks.