Mousing through Large Image

programming flash
1

I am attempting to get a large portrait image (scaled to the full width of the screen) to be able to show the excess top part by moving the mouse up, and viewing the bottom by moving the mouse down.

So far, I have only been able to achieve the opposite (mouse down, image goes up, mouse goes up, image goes down), because I want the user to be able to click on certain portions of the image.

onClipEvent (load) {
    _y = 0;
    speed = 5;
}
onClipEvent (mouseMove){
    endY = _root._ymouse;
}
onClipEvent (enterFrame) {
        _y +=(endY-_y)/speed;
}

I found that if i changed this line

        _y +=(_y-endY)/speed;

it achieved the effect of pushing the image in the right direction, however, instead of keeping the image withing boundaries in the previous coding, this slight change pushes the image of the page fast.

Any suggestions?

bbbco