Best way to listen?

integer ChannelA = 15 ;
integer ChannelB = 16 ;

integer ListenA ;
integer ListenB ;

integer AListening ;
integer BListening ;

integer TimerA = 0 ;
integer TimerB = 0 ;

default
{
    state_entry()
    {
        ListenA = llListen(ChannelA, "", NULL_KEY, "") ;
        llListenControl(ListenA, FALSE) ;
        AListening = FALSE ;
        BListening = FALSE ;
        llSetTimerEvent(1.0) ;
    }

    touch_end(integer total_number)
    {
        TimerA = 0 ;
        if (!AListening)
        {
            llListenControl(ListenA, TRUE) ;
            AListening = TRUE ;
        }
        TimerB = 0 ;
        if (!BListening)
        {
            ListenB = llListen(ChannelB, "", NULL_KEY, "") ;
            BListening = TRUE ;
        }
        llDialog(llGetOwner(), "DialogA", ["Pick me!"], ChannelA) ;
        llDialog(llGetOwner(), "DialogB", ["No me!"], ChannelB) ;
    }
    timer()
    {
        if (AListening && (++TimerA > 60))
        {
            llListenControl(ListenA, FALSE) ;
            AListening = FALSE ;
            llOwnerSay("A stopped listening") ;
        }
        if (BListening && (++TimerB > 60))
        {
            llListenRemove(ListenB) ;
            BListening = FALSE ;
            llOwnerSay("B stopped listening") ;
        }
    }
}