I have a website that has a design like google web store. This is what it looks like:

if you’ll notice in the bottom area the 2 boxes are not filling up the space above.
boxes is wrap by ul and items are in li. The list items are float by left and ul is has a clear.
Here is the link for jsfiddle http://jsfiddle.net/wTCKr/
Please suggest CSS or any JS that will fix this. Thank you.
If you want large boxes on the right, you will need to float them right so that the smaller boxes on the left will fill in correctly.
See this updated JS Fiddle fork.
This will not solve the problem if you put the big box in the middle. If you also need to support that case, I would suggest it’s time to use absolute positioning and some jQuery or JS to do the layout for you.
Update: I enjoy a quick challenge, so I wrote some JS to do absolute positioning for you. I used jQuery, but you can convert it to straight JS if you don’t use jQuery on your site. The code assumes that you have the right number of boxes in a valid order (eg. you can’t put a big box on the last row if all the other rows are filled with small boxes).