Position absolutely positioned DIV relative to (also absolutely positioned) parent DIV?

Question

This is one problem I always have when i\'m fixing layouts. I\'ve got a absolutely positioned DIV, I place a child-DIV inside which also needs to be absolutely positioned. But I

Answer 1

If you're already absolutely positioning one div, can't you just add the two offsets together for the child? e.g. for #one to be at 10,10 and #two at 10,10 relative to #one,

#one {
    position: absolute;
    left: 10px;
    top: 10px;
}

#two {
    position: absolute;
    left: 20px;
    top: 20px;
}

Or is it something fancier, like #one locking to top-left corner and #two to bottom-right of #one, in which case basic math doesn't work that way? In that case, an extra div is probably necessary.

Or am I just tired and missing something?