I lost my _ymouse position (FMX)

I know this is simple but I can’t find a tute on determining the y mouse position. I’m sure I saw something in the AS Dictionary but I just can’t find it now.

All I’m trying to do is have the _root mc goto frame 3 when the user’s _ymouse is <= 60px.

I was going to put my AS attempt here but it’s so out of wack I thought I’d be laughed out of math class.

So, rather than embarass myself further, does anyone know of a tute for this or something like it?

Thanks.