Remove white space between 2 modules

Hi,
I have a module in Top1 and another module in Top2 position. But there is a white space between the two. How do I get rid of that? Thanks.

Could you please provide me with a URL to your website, either here or via PM (click the “Private Message” text underneath my avatar) so that I may analyze it? It is a lot easier for us to diagnose issues when we have a live site to examine.