Try to use this simple method:
function event_blahblah()
{
var snd_once = 1; // ******
while(1)
{
my.alpha = 70;
pick_function();
scan_you();
// play sound only if skill6 is "0" and snd_once is "1":
if(my.skill6 == 0 && snd_once) // ******
{
snd_play(SND_FINAL, 100, 0);
snd_once = 0; // don't allow to play again
}
// till we release mouse_left:
if(!mouse_left && snd_once == 0){snd_once = 1;} // ******
wait(1);
}
}
I've commented it, plus add "* * *" on those lines, where I've add anything.
I won't recommend approach with another wait loop, cause that will stop the previous one, till you release the button.
