How to display column footer immediately without any spaces after details band

Problem
This is my report design in iReport:

Here is the Detail property and Column Footer property setting:

But...as I generate pdf, there has unnecessary spaces between Detail band and Column Footer band.

Solution

Step1. Right click --> property

Step2. Check the "Float column footer" property

Then this problem will be solved. There will not have any spaces between Detail band and Column Footer band.