Equal unique ID's in differente Activities

Equal unique ID's in differente Activities

I'm wondering, what happens if I declare two unique ID's in 2 different
activities? The ID's have the same name and are declared as unique (@+id)
.. Is there any collision of ID's ? When I call the Id in the code of the
second activity, is going to have any problem, what ID is it going to
call?
Thanks :)