default
{
    touch_start(integer total_number)
    {
        // Sends the message 0, "Touched.", NULL_KEY to all scripts in this prim,
        // that contain a link_message() event handler. That would _this_ script
        // if it has one.
        llMessageLinked(LINK_THIS, 0, "Touched.", NULL_KEY);
        // The 'LINK_THIS' constant makes llMessageLinked ONLY send the message
        // to the current prim.
        // It's the same as using 'llGetLinkNumber()' to return the current link number.
    }
}

default
{
    // Waits for another script to send a link message
    link_message(integer sender_num, integer num, string str, key id)
    {
        llSay(0,str);
    }
}