Problem with facial expressions and linksets

Can anyone help me with this? I can see where the problem lies, I think, but can't see my way round it. I have my two anims running OK, each with the appropriate facial expressions, but the problem is that when I link them up, if I get off the pose ball, my mouth stays open until the person flogging me gets off his pose ball, too.

I started with this:

// Open Pose Ball
// from Dolyn Foley
// Feel free to ask me about this code
// Please pass it on, a la GPL

list gAnimations = ["express_open_mouth" ];

restartAnimations()
{
    integer i ;
    integer max = llGetListLength(gAnimations) ;
    string ani ;
    for (i=0;i<max;i++)
    {
        ani = llList2String(gAnimations, i) ;
        llStopAnimation(ani) ;
        llStartAnimation(ani) ;
    }
}
string sitAnimation = "";

// if sitAnimation is left blank
// the script will grab the first animation in the container.
// if a value is set, it will use that instead.
//string sitAnimation = "yoga_float";


default {
    on_rez(integer start_param) {
        llResetScript();
    } 

    state_entry() {
        llSetText("Sit to Pose", <0.0,1.0,0.0>, 1);
        llSitTarget( <0,0,0.75>, ZERO_ROTATION );

        // if blank, we look in inventory
        if (sitAnimation == "") {
            sitAnimation = llGetInventoryName(INVENTORY_ANIMATION, 0);
            
            // oops, use default
            if (sitAnimation == "") {
                sitAnimation = "sit";
            }
        }
    }


    // Using state to control sitting
    // If you're in this state, no one is sitting
    changed(integer change) {
        if (change & CHANGED_LINK) {
            key avatar = llAvatarOnSitTarget();
            if ( avatar != NULL_KEY )  {
                llRequestPermissions(avatar,PERMISSION_TRIGGER_ANIMATION);
                 llSetTimerEvent(0.5) ;
            }
        }        
    }

        
    run_time_permissions(integer parm) {
        if(parm == PERMISSION_TRIGGER_ANIMATION) {
            llStopAnimation("sit");
            llStartAnimation(sitAnimation);
            state sitting;
        }
    }    
}
  

state sitting {
    state_entry() { //intentionally left blank
    }

  
    touch_start(integer total_number) {
    }

    // Assume sitting, thus any CHANGED_LINK means standing.        
    changed(integer change) {
        if (change & CHANGED_LINK) {
            llStopAnimation(sitAnimation);
            llSetTimerEvent(0);
            llResetScript();
        }        
    }
timer()
    {
        restartAnimations() ;
        
    }
}

But the trouble with that was that, while it worked fine when I was the only person on the pose ball, but when someone got onto the other ball in the linkset to join me, it fired off " if (change & CHANGED_LINK)" and stopped the timer that was keeping my mouth open.

So.. I tried this:

string sitAnimation = "";
string sittext = "Floggee";
list gAnimations = ["express_open_mouth" ];
integer p;

restartAnimations()
{
    integer i ;
    integer max = llGetListLength(gAnimations) ;
    string ani ;
    for (i=0;i<max;i++)
    {
        ani = llList2String(gAnimations, i) ;
        llStopAnimation(ani) ;
        llStartAnimation(ani) ;
    }
}

default {
    on_rez(integer start_param) {
        llResetScript();
        p = llGetNumberOfPrims();
    }

   state_entry() {
        llSetText(sittext, <0.0,1.0,0.0>, 1);
        llSitTarget( <0,0,0.75>, ZERO_ROTATION );
        llSetTimerEvent(0.5);
   // if blank, we look in inventory
        if (sitAnimation == "") {
            sitAnimation = llGetInventoryName(INVENTORY_ANIMATION, 0);
            
            // oops, use default
            if (sitAnimation == "") {
                sitAnimation = "stand";
            }
        }
    }
     changed(integer change) {
        if (change & CHANGED_LINK) {
            key avatar = llAvatarOnSitTarget();
            if ( avatar != NULL_KEY )  {
                llRequestPermissions(avatar,PERMISSION_TRIGGER_ANIMATION);
            }
        }        
    }
       run_time_permissions(integer parm) {
        if(parm == PERMISSION_TRIGGER_ANIMATION) {
            llStopAnimation("sit");
            llStartAnimation(sitAnimation);
       

            state sitting;
        }
    } 
 

        
    }
    state sitting {//intentionally blank
    state_entry() {
    }
    touch_start(integer total_number) {
    }

    // Assume sitting, thus any CHANGED_LINK means standing.        
    changed(integer change) {
        if (change & CHANGED_LINK) {
            if (llGetPermissions() & PERMISSION_TRIGGER_ANIMATION)
           { llStopAnimation(sitAnimation);
           if (p = llGetNumberOfPrims()) //bad- should be     if (p == llGetNumberOfPrims())
            llResetScript();}
        }        
    }
    timer()
     {
        restartAnimations() ;
        
    }

}

which not only keeps the facial expression going when my tormentor gets on his pose ball, which is what I want, but also keeps it going until he gets off and (p = llGetNumberOfPrims()) again . That's not the end of the world, but it would be nice to stop my facial expression when my animation stops, too.

Any suggestions? I'm sure there's a solution, but I can't quite see how to approach it.

Update.. I spotted an error in the code.. if (p = llGetNumberOfPrims()) -- I've fixed that to if (p == llGetNumberOfPrims()) and made a couple of other adjustments which I will post when next I am in world, but it still ain't working properly.