how to set global vo(value object) ?

as title as said.i put some information into vo,for example:

i saved username and password into vo(value object)after user login in EP.i hope i can get the value any time from the vo.that's equivalent to the function in jsp :

session.setAttribute("vo","xx");

VO vo =(VO)session.getAttribute("vo");

u know we cann't do it as that in web dynpro project.

i know i can set value to context of view,even shared it in the same one component.but i cann't get the value in the others compoent.

in short ,i wanna: once set value, anywhere get it.

thanks in advance.