element position inside scrollable div tag

[unixfreak compiler]

I'm using the algorithm listed beow to get the position of an element.
Some elements are located inside DIV tags that can scroll. The
scrolling doesn't seem to change the X and Y coordinates I get back
from this algorithm so it ends up being wrong.

What do I need to do to include the effects of the scroll bar?

- john

function getElementPosition(elementID) {

var element = document.getElementById(elementID);
if (element == null) { return null; }
var xPos = findPosX(element);
var yPos = findPosY(element);

return { x : xPos, y : yPos };
}

function findPosX(obj) {

var curleft = 0;

if (obj.offsetParent) {
while (obj.offsetParent) {
curleft += obj.offsetLeft
obj = obj.offsetParent;
}
} else if (obj.x) {
curleft += obj.x;
}

return curleft;
}

function findPosY(obj) {

var curtop = 0;

if (obj.offsetParent) {
while (obj.offsetParent) {
curtop += obj.offsetTop
obj = obj.offsetParent;
}
} else if (obj.y) {
curtop += obj.y;
}

return curtop;
}