//Write your greeting in the next line
string greeting="Greet you!";
integer clears;


list visitors;
integer i;
list temp;
default
{
    state_entry()
    {
        llSetTimerEvent(.01);
    }

    timer()
    {
       temp= llGetAgentList(AGENT_LIST_PARCEL,[]);
       {
           if(llGetListLength(temp)>0)
           {
               //llOwnerSay(llDumpList2String(temp,", "));
                for(i=0;i<llGetListLength(temp);i++)
                {
                    if(llListFindList(visitors,[llList2Key(temp,i)])==-1)
                    {
                        visitors+=llList2Key(temp,i);
                        llRegionSayTo(llList2Key(temp,i),0,greeting);
                    }
                }
            }
        }
        if(llGetListLength(visitors)>700)
        {
            clears+=200;
            visitors=llListReplaceList(visitors,visitors,200,800);
        }
        llSetTimerEvent(60);
    }
    touch_start(integer tickles)
    {
        integer count = clears+llGetListLength(visitors);
        if(llDetectedKey(0)==llGetOwner())llRegionSayTo(llGetOwner(),0,(string)count+" visitors since you launched");
    }
}