Android - Slider animation between activities

Android - Slider animation between activities

I have to implement a simple animation between 2 activities: I've already
implemented some simple animations, but last one is a little bit more
difficult to realize.
The animation should act like this: Activity A (on screen) slides from
YDelta = 0 to Ydelta = -100%. In the meantime, Activity B is already in
its final position (it doesn't move, no translation needed...) and it's
slowly showed.... Like a courtain...
I'tried in this bad way:
overridePendingTransition(R.anim.no_anim, R.anim.slide_to_top);
no_anim:
<?xml version="1.0" encoding="utf-8"?>
<translate android:fromYDelta="0" android:toYDelta="0"
android:duration="2000"/>
slide_to_top:
<?xml version="1.0" encoding="utf-8"?>
The result is not correct: Activity B (that is binded to no_anim) is
immediatly showed on the screen, and so Activity A simply disappear...
How can I solve my problem?
TY and BR!