help in radioButtons

[lflc]

Hi,

I am having a problem in the Radio Buttons.

I am developing a GUI in witch i am using radio buttons to select correct options, but i have a problem that i cannot solve.

In every group of radio buttons the 1st button is appears always select, but actually is not selected, the only way of selecting it is by choosing other button and then choose again the 1st button.
does anyone know how to solve this? I would like that in the begging none of he buttons appear selected, only select button after clicking on it.