Yeah, how stupid am I, I've thought about this before, but I guess the listbox would dissapear after a mouse click, because it's pass the textbox lostfocus,
so by adding this.visible = .t. on listbox gotfocus(), everything is just like what I want.
Thanks Eric, and thanks to everyone who replied this question.
Senna Dwipayana
Being good is better
Being better is a bless