What this is is that it makes stars (or other stuff) go from alpha 0 to alpha 100 and backwards. Don't sure if this have been done already but this is a pretty simple way to do it.
SAMPLE
Ok, make a new MC and make a star in it.
Place this code in it:
onClipEvent(enterFrame){
_alpha<=0?plus=1:0
_alpha>=100?plus=0:0
_alpha+=(plus)*5;
_alpha-=(!plus)*5;
}
Even thought this is FOSS Material I still want to explain the code for you.
onClipEvent(enterFrame){
_alpha<=0?plus=1:0
Makes the var plus true if alpha is lower than 0, same as if(_alpha<=0){plus=1}
_alpha>=100?plus=0:0
Makes the var plus false if alpha is higher than 100
_alpha+=(plus)*5;
Makes the alpha of the MC rise if the var plus is true
_alpha-=(!plus)*5;
Makes the alpha of the MC lower if the var plus is false
}
~GWHC
