function that can be called by event and from code?

My question is if there's a technique such as this that would allow you to have one function be called both by an event listener, and manually by having the function called out in the code. It seems with what I know you can only have one function work one way or the other, but I can't believe that's the case...

Also, I know you could say

myfunction(e:Event){
}

and this would at least allow any event type to call it? I also wonder what "e" actually is. Is this just shorthand for "event"?

Thanks!
Devin