NWScript:

// Determine if I'm "is dancing", and if not, to start (check local variable)
    if(GetLocalInt(OBJECT_SELF, "iIsDancing") != 1)
    {
        // Find the Player Character closest to me
        object oClosestPC = GetNearestCreature(CREATURE_TYPE_PLAYER_CHAR, PLAYER_CHAR_IS_PC);
        // Find the tag of the area I'm currently in
        string sMyCurrArea = GetTag(GetArea(OBJECT_SELF));
        // Find the tag of the area oClosestPC is in
        string sClosePCArea = GetTag(GetArea(oClosestPC));
        // Make sure that the closest player is in the same area as me
        if(sClosePCArea == sMyCurrArea)
        {
            // Remember that I'm dancing
            SetLocalInt(OBJECT_SELF, "iIsDancing", 1);
            ActionPlayAnimation(ANIMATION_FIREFORGET_VICTORY2);
            DelayCommand(3.0, ActionPlayAnimation( ANIMATION_LOOPING_TALK_LAUGHING, 3.0, 2.0));
            DelayCommand(3.0, PlayVoiceChat(VOICE_CHAT_LAUGH));
            DelayCommand(5.0, ActionPlayAnimation( ANIMATION_FIREFORGET_VICTORY1));
            DelayCommand(8.5, ActionPlayAnimation( ANIMATION_FIREFORGET_VICTORY3));
            DelayCommand(11.0, ActionPlayAnimation( ANIMATION_LOOPING_GET_MID, 3.0, 2.0));
            DelayCommand(14.5, PlayVoiceChat(VOICE_CHAT_LAUGH));
            DelayCommand(13.0, ActionPlayAnimation( ANIMATION_FIREFORGET_VICTORY3));
            // Wait until I'm almost finished with my dance, then reset my
            // iIsDancing local int so the process will restart. This
            // should prevent an npc's action queues from recieving too
            // many commands, by waiting until most of them have finished
            // before restarting the sequence. It doesn't wait for all
            // the animations to complete, otherwise 'pauses' between
            // the animation sequences will happen while waiting for
            // the next heartbeat to run.
            DelayCommand(12.0, SetLocalInt(OBJECT_SELF, "iIsDancing", 0));
        }
    }