I am sorry, but your examples fail to carry your intent, as they make no sense... Once you done one background() call in draw(), there is no point to make another (it will just erase the previous one and previous drawings, that's why this call is usually the first one in draw()).
Moreover, if i == 1, it cannot be equal to 2, so the inside test is pointless. (It can make sense for tests like > or <=)
In general, programmers advise against using the same variable for different purposes, as it can be confusing when re-reading the code: it is better to make new variables with distinct, clear names.

Perhaps you should explain what you are trying to achieve instead of concentrating on syntax.

[EDIT] I deleted your "answer" to your old thread on Reactivision, identical to this one, because it is unrelated and, more importantly, duplicating questions can only disperse/dilute/duplicate efforts of those willing to answer.

Thank you for your reply.

I don't know Reactivision, so I fail to understand what an ID is, or why you want to use a same "symbol" (whatever it can be) for various "tasks" (whatever they can be). Technically, I think it is possible, though.