laptop - Is it safe to keep the Asus notbook plugged in to AC power while working?

I sometimes work the whole day with the machine. at that time, I keep my laptop plugged in the the ac adapter and work with the machine. When im done, I remove it. People say its ok to do this because most of the laptops will auto turn off power to the battery if its full and direct them to the notebook. Is this true for Asus?