Quick fix: Passing a int Variable into a function

programming flash
1

I can’t seem to get this to work:

var i:int = 0;

function count(a:int):void
{
a++;
}

count(i);
count(i);
count(i);

trace(i);//traces 0

Is there a way I can make it do it’s math, to the variable itself, without some crazy solution or using objects to hold the variables?