Please Help! - Calling functions from another point in the timeline

programming flash
1

I want to call a function, lets say

function ypos (object, pos) {
Tweener.addTween(object, {_y:pos, time:0.8, transition:"easeOut"})
}

and this is in the maintime at 0.
let say i have another object, statusbar, and this is at timeline 20, and i call the function


_root.ypos(_root.statusbar, 30);

but it does not work! please help!