Ok, my question is how to make some actuator to executes when animation of another object is in N-th frame…like in “Adobe Flash ActionScript”. For instance: we have tow objects, one of them is with 100 frames of animation and we want in the 50-th frame of its animation the other to start executing its animation from the first frame…or worst 
from 10-th frame…so is it possible in blender…and how if it is. This is very important for me…please help if anybody know something about this…some tutos…tecniques…or .blend samples.
Did you try to do it with a “message” actuator? When your first object animation starts, set a timer to count time and when the time is right it sends a message to the other object. Other object receives the message and starts his animation.
Hope this helps if I got your question right…
you can tell both the IPO and the action actuator to run on a property’s value.That way you have total control of what frame is playing, with a little tweaking you can determine the speed it is playing at.
like spacestrudel pointed out, you can trigger the event with a message actuator.