function countDown(container, targetdate){
if (!document.getElementById || !document.getElementById(container)) return
this.container=document.getElementById(container)
this.currentTime=new Date()
this.targetdate=new Date(targetdate)
this.timeIsUp=false
this.updateTime()
}

countDown.prototype.updateTime=function(){
var thisobj=this
this.currentTime.setSeconds(this.currentTime.getSeconds()+1)
setTimeout(function(){thisobj.updateTime()}, 1000) //update time every second
}

countDown.prototype.displaycountdown=function(baseunit, functionref){
this.baseunit=baseunit
this.formatresults=functionref
this.showresults()
}

countDown.prototype.showresults=function(){
var thisobj=this

var differenceTime=(this.targetdate-this.currentTime)/1000 //difference btw target date and current date, in seconds
if (differenceTime<0){ //if time is up
this.timeIsUp=true
this.container.innerHTML=this.formatresults()
return
}

var oneMinute=60 //minute unit in seconds
var oneHour=60*60 //hour unit in seconds
var oneDay=60*60*24 //day unit in seconds
var oneYear=60*60*24*365 //years unit in seconds
var yearfield=Math.floor(differenceTime/oneYear)
var dayfield=Math.floor((differenceTime-yearfield*oneYear)/oneDay)
var hourfield=Math.floor((differenceTime-yearfield*oneYear-dayfield*oneDay)/oneHour)
var minutefield=Math.floor((differenceTime-yearfield*oneYear-dayfield*oneDay-hourfield*oneHour)/oneMinute)
var secondfield=Math.floor((differenceTime-yearfield*oneYear-dayfield*oneDay-hourfield*oneHour-minutefield*oneMinute))

var daysfield=dayfield-1
var hoursfield=hourfield-1

if  (daysfield==-1){daysfield=364}
if  (hoursfield==-1){hoursfield=23}

this.container.innerHTML=this.formatresults(yearfield, daysfield, hoursfield, minutefield, secondfield)
setTimeout(function(){thisobj.showresults()}, 1000) //update results every second
}

function formatresults(){
if (this.timeIsUp==false){//if target date/time not yet met
var displaystring=arguments[0]+"&nbsp;"+arguments[1]+"&nbsp;"+arguments[2]+"&nbsp;"+arguments[3]+"&nbsp;"+arguments[4]
}
else{ //else if target date/time met
var displaystring="LANDSKRONA 600 ÅR!!!"
}
return displaystring;
}

function countdown() {
var futuredate=new countDown("countdownDiv", "March 20, 2013 00:00:01")
futuredate.displaycountdown("days", formatresults)
var currentyear=new Date().getFullYear()
}