How to center div?

Question

I have a problem with centering div in HTML (vertical & horizontal). My code looks something like this:

SOME HTML
         


        

Answer 1

Should be fine to use just CSS:

here is the demo

#container{
    width: 366px;
    height: 274px;
    margin: 50%;
    top: 50%;
    left: 50%;
    position:absolute;
    top:0;
    bottom:0;
    left:0;
    right:0;
}​