How can I shift up a div and all divs that follow it?

Problem :

I have two divs that I want to appear on top of each other. I was able to do this by setting the top in css. My problem is that now there is a big gap where the div used to be. I would like to get all of the subsequent content to float up and fill that gap.

You can see the fiddle here: http://jsfiddle.net/MzvC4/

Any suggestions on how to achieve this?

Solution :

Should be able to do this:

            #Navigation{
                position:absolute;
                margin-top:-250px; //or whatever px it is
            }

http://jsfiddle.net/MzvC4/1/