[F5] Trouble with variables

Im still fairly new to programming with actionscript, but this isn’t a largely complicated problem (I dont think so anyway).

Anyway, what I am trying to accomplish is:

-declare a variable
-give that variable a value based on the frame number the movie is currently on
-then add 1 to that variable

so in effect, if the movie is on frame 4 for example, the value of the variable would be 5. The code is in a button, that controls a MC that is on the stage (it doesnt interact with the _level0 stage, just the MC its in, its for a scrolling menu)

The code Im trying to use is

var scroller = _currentframe +1;


I know my syntax is wrong, but as I’m still new I am not totally sure what I am missing, so any hints would be grealty appreciated! Thanks!