Actionscript

In Actionscript, what would this mean:

if (-1(-1(eval("someVariable"))) == eval("someVariable"))

Particularly the nested -1s. What do those do?

-1 is not a function

No, it's your IQ. Two posters already explained that it's, well, uh... -1. A number which, if used for multiplication, only changes the sign, not the unsigned value of any other number, thus being ideal to turn something positive into its negative equivalent - or vice versa, should the original value already be negative.

And as #8 rightly said, negating something twice returns the original value, thus making the whole operation pointless.