Movie clip depth

I know this topic has been beaten to death in these forums but I had a quick question I was hoping someone could answer. I made a calendar that populates using duplicate movie clip. I have an additional mc to display event data that plays when the user clicks on one of the calendar dates.

I need the second mc to always be on top. By default, it has a depth of approx. -16000. To put it on top I used.

onClipEvent(load){
this.swapDepths(this._y)
}

This works fine for the first displayed month, but when I go to another month or year, this clip defaults back to it’s original depth of -16000.

When I go to a new month or new year, my AS increments the year or month value then re-runs the duplicate mc function to populate the calendar.

the swapdepths takes place on the first frame while the duplicate mc function is occuring on the third frame. When the buttons to change the year/month are pressed, frame 3 is re-played.

I was able to get around this using attachMovie, but my question is, why does the depth default back to -16000 if movie runs only frame 1 only one time and never again? Should the depth stay at the new depth?

This is by no means an urgent issue, as I said I got around it with attach movie, it’s just more to satisfy my own curiosity.

Thanks.