AS3 escape the room game

hi all

i am making a escape the room in flash in by game i have 4 rooms with different objects inside and when I click on one of the object it disappears in to the inventory but I am having a problem with the inventory when move to room 2 and go back to room 1 the object i pick up disappears from the inventory back to the stage but i what the to stay in the inventory when i have pick it up and i what to be able to go to different room without the object returning i am working in AS3 please help

thank you