Problem with $.data()

Hello,

I have a little problem, I use the function .data() to store some things on an element

$(this).data("menu", { type: "normal", state: "selected"});

This works fine, but when I go to modify the "state" like

$(this).data("menu", {state: "deselected"});

I lost the menu.type, how I can change state without lost type?

Thanks