Replacing user controls after removing, on the asp.net web page

I am trying to remove/add user controls on a asp.net web page and what I want after removing an user control is that the another user control takes the place of the removed one. In other word the controls should be able to reposition themselves. I have to say that I put 6 user controls in a table with 3 columns and 2 rows.Actually, when I remove a control in one cell of the table, the cell space remains empty. I want that the remaining user controls to being able repositioning and take the place of the removed control? Is there any way with <div> ans css style or any other solution?

Please help me!!!
Mimi