Countdown dinamico

[expecimen]

Saludos tengo el siguiente java scrip el cual es Countdown es bastante bueno me dice los días que faltan en días, horas minutos y segundo pero cuando llega la fecha limite no coloca el letrero que diga: HOY ES EL GRAN EVENTO.

<form name="count">
<input type="text" size="69" name="count2">
</form>


<script>
var before="PARA EL EVENTO"
var current="HOY ES EL GRAN EVENTO"
var montharray=new Array("Jan","Feb","Mar","Apr","May","Jun","Jul","A ug","Sep","Oct","Nov","Dec")

function countdown(yr,m,d){
theyear=yr;themonth=m;theday=d
var today=new Date()
var todayy=today.getYear()
if (todayy < 1000)
todayy+=1900
var todaym=today.getMonth()
var todayd=today.getDate()
var todayh=today.getHours()
var todaymin=today.getMinutes()
var todaysec=today.getSeconds()
var todaystring=montharray[todaym]+" "+todayd+", "+todayy+" "+todayh+":"+todaymin+":"+todaysec
futurestring=montharray[m-1]+" "+d+", "+yr
dd=Date.parse(futurestring)-Date.parse(todaystring)
dday=Math.floor(dd/(60*60*1000*24)*1)
dhour=Math.floor((dd%(60*60*1000*24))/(60*60*1000)*1)
dmin=Math.floor(((dd%(60*60*1000*24))%(60*60*1000) )/(60*1000)*1)
dsec=Math.floor((((dd%(60*60*1000*24))%(60*60*1000 ))%(60*1000))/1000*1)
if(dday==0&&dhour==0&&dmin==0&&dsec==1){
document.forms.count.count2.value=current
return
}
else
document.forms.count.count2.value=dday+ " days, "+dhour+" hours, "+dmin+" minutes, and "+dsec+" seconds "+before
setTimeout("countdown(theyear,themonth,theday)",10 00)
}
//enter the count down date using the format year/month/day
countdown(2011,9,26)
</script>

Espero me puedan ayudar