Sound question

Hello,
I am trying to create full flash web started few days ago
and now i have some problem assembling it
the current problem i got is Slider

i follow step by step tutorial on kirupa for volume slider
but somehow the slider goes eratically
the dragger always follow mouse and won’t stay
usually it happen if i put the dragger to the most left or right
what i already done wrong ?

and 2nd is there a way to make the sound run when loading complete ? (rather than waiting for play command for play button)
or the only way to do it is place the sound on mc ?

Thanks alot for everyone that willing to spend time help me ^^
and sorry for newbie question