GridBagLayout - to much vertical space between components

GridBagLayout - to much vertical space between components

I am using gridbaglayout.
There is some code:
constraints.gridx = 0;
constraints.gridy = 1;
grid.setConstraints(s, constraints);
s.setSelected(true);
this.add(s);
constraints.gridx =0;
constraints.gridy = 2;
grid.setConstraints(c, constraints);
this.add(c);
where c and s both belong to a radiobutton. What happens is that I have a
lot of vertical space between a and c which I do not wish to have. How can
I change this?