Scrolling a MC

Hi everyone. I’m really trying to find a tutorial somewhere on the internet where is explained how to scroll a mc using a scrollbar. I did this tutorial yesterday explaining how to scroll the mc with buttons. Then i decided to do the scrolling with the buttons and with a scrollbar. I created the scrollbar itself but can not think of a way of linking the _yposition of the dragger with the _yposition of the mc.
What i’ve done so far is down there. If somebody knows the answer just give a hint, not the whole code, i’ll try to finish it and i’ll post it later to show the result.
Will be very greatful if someone helps.