//Touch and get near avatars in a dialog menu.
//By Kahiro Watanabe
//GPL share it!

//menu listener
integer listener;
integer sensorChannel;

// range and arc for the sensor
float range = 15.0;
float arc = PI;

list avatarsKeys;
list avatarsNames;

menu(key user,integer channel,string title,list buttons)
{
    listener = llListen(channel,"","","");
    llDialog(user,title,buttons,channel);
    //remove listener if there's no activity in menu
    llSetTimerEvent(20.0);
}

integer randomNumber()
{
    return (integer)(llFrand(99999.0) * -1);
}

default
{
    touch_start(integer total_number)
    {
        //only owner can access the menu
        if (llDetectedKey(0) == llGetOwner())
        {
            llSensor("","",AGENT,range,arc);
        }
    }
    sensor(integer total_number)
    {
        integer i;
        key tempId;
        avatarsKeys = [];
        avatarsNames = [];
        i = 0;
        while ((i < total_number) && (i < 12))
        {
            tempId = llDetectedKey(i);
            avatarsKeys = avatarsKeys + tempId;
            avatarsNames = avatarsNames + llKey2Name(tempId);
            i = i+1;
        }

        sensorChannel = randomNumber();
        menu(llGetOwner(),sensorChannel,"Select an avatar...",avatarsNames);
    }

    listen(integer channel,string name,key id,string message)
    {
        if (channel == sensorChannel)
        {
            integer pos = llListFindList(avatarsNames,[message]);
            if (pos > -1)
            {
                llSay(0,message + "'s key is " + llList2String(avatarsKeys,pos));
            }
        }
    }
    timer()
    {
        llListenRemove(listener);
        llSetTimerEvent(0.0);
    }
}

This simple script can be controlled only by owner, it will generate a list of near avatars and put it in a menu, when the user selects one it will show its key. You can do useful stuff like give an object or animate it, etc etc etc.