Any benefit from putting 'this.' infront of everything?

1

Hi,
I was wondering if there is any benefit from ‘this.’ infront of everything ?

for eg are these the same ?

var a:Sprite = new Sprite();
this.a.x=10;
a.x=10;

is there a performance difference? is it considered more readable? I cant seem to find a difference but I have come across code where it is consistently included.

Thanks,

S.