Variable in AddEventListener

Hi guys,

I got a quick and newbie question on variables in javascript

I was wondering is it possible to get the updated value in a whenever I scroll the scrollView?

Many thanks!

Code example:

var a = "1";
scrollView.addEventListener('scroll',function(e){
    Ti.API.info('a' + a) // gives me 1 when i scroll every time (It didn't increase to 2,3,4,5,6,etc,etc)
    a++ 
});