How to refresh dynamically binded menu

Question

Hi all
 
Iam using MainMenu first_menu = new MainMenu(); to create new menu item in .net windows based application. all items in the menu comes from database by using certain queries.but when i added new menu item changes not reflecting in the menuitem.I invoke the procedure to bind menuitems after addition of menuitems to the table.but its not works.but when i dispose the form and call the form again it works.but its not possible to dispose and call it again after each addition.if do so the menu window come in front of already taken window. how to solve it
 
THANKS IN ADVANCE
 

Amrutha