using interrupts...basic use query

On the piece I am currently building I have an switch that the viewer can effect, and my sketch looks for the state change in the loop() function. Once it reads the switch, and it has been effected, the program moves to another function and runs until the end. What I would like to do is two things - 1) use interrupt(s) so that as soon as the viewer effects the switch it jumps to the second far so good, I think I can handle this no problem. The second thing though, is that if the viewer decides to move on I want it to return to the loop() function instead of continuing execution in the longer second function.

My question, is it simply a matter of using the two interrupts in a complimentary fashion? Is there any problem with this working? Any gotchas? Anyone ever do something similar? Anyone have any examples?

I am going to work on it in the morning...I wouldn't even normally ask such a general question without hacking on it for a while, but me and my sculpture leave for Vienna Wednesday morning and I really want to get it to work the way I want. Many thanks in advance!!!

Here is where I am going btw -