This programms open a frame from a menu 
Epi tis ousias paizei me to visibility toy subframe
Alla xrisimopoiei kai tin methodo dispose gia na kleisei to main frame
(H diafora tis dispose apo to visibility einai oti epi tis ousias
eleytheronontai ola ta resources pou aforoun sto main frame alla kai sta
children components tou.