Non-liner changing of _alpha property

Question

I have following problem: I try to modify _alpha property of
an object using AS, increasing the _alpha value non-linearily
I have three frames movie.
On the fisrt frame there is a mc called "OBJECT", with _alpha
set to "0", plus this AS:
speed = 10;
beg = OBJECT._alpha;
end = 100;
difference = end-beg;
move = difference/speed;
OBJECT._alpha = beg+move;
on the second frame I ask if the _apha value has already
reached the "end" value (which is set on the first frame), if NOT I
go back for the first frame and if YES I would continue my movie
if (OBJECT._alpha<(end-1)){
gotoAndPlay(1);
} else {
gotoAndPlay(3);
BUT thing is that the _alpha value NEVER reach the "end"
value set on the first frame. Just in case the "speed" value is set
for "2", every other value DOES NOT WORK ... and that is the
question - WHY?
thanks for any helps

Answer 1

that's not correct. flash represents the alpha as a number
from 0 to 255 and that's not relevent to your problem.
what is causing your problem is that flash allows only 8
significant digits to represent an object's alpha and you chose a
series of alpha's that converge too slowly. if you'd chosen speed =
2 (or 3) you'd have no problem.
or if you'd performed your increments on a variable that
stored the alpha you would realize the usual flash 15 digit
accuracy and could have used speed = 10.