通过javascript在contenteditable div上获取插入符号坐标。

I've been searching a lot but i could't find a way to get (X,Y) coordinates for the caret on a content editable div,there's a lot of content on the web about this,but the problem none of the pages i found get the coordinates according to the top of the div,so my question in a simpler way is:I've been searching a lot but i could't find a