AS3, textfield autoscroll

I have a textfield with many rows
I want to display a specific row (n) on the first line when the program is first run (without user command)
If I don't move the mouse, only 1 row is always displayed on the first line
"textfield.scrollV = Math.max(0, n);" doesn't work
However, it works fine for clicks assigned to buttons
Any solution?