glutAttachMenu(button)

ex: glutAttachMenu(GLUT_MOUSE_RIGHT);
once I click the right mouse button, the menu pops up immediately

How can I make the menu pop up after “mouse up” or after releasing the mouse button??

I know how to use glutMouseFunc(int button, int state, int x, int y),
but I just started on glut menus.

Help pls thx in advance ^^