prevent fields from spreading over available space

when a form is say 800px wide, and I have only two small fields to show, these two fields will not be placed on the left side of the form, instead there’s a lot of distance between the fields (and labels).

How can I accomplish that both fields/labels are as much to the left as possible?

Here’s an example using blocks. Upper block contains 2 fields, lower block a lot of fields. Lower block is acceptable, but because this block makes the form wide, the fields in the upper block are screwed up.

Re: prevent fields from spreading over available space

nobody any clue?