//Written by Bogdan Blaszczak/BlaTek
//blatek@25.pl
//original version @ http://js.webhelp.pl/js/prz/blatek/datepicker.html
//Modified by PablO @ 2005
//full desc available @ http://piskorz.info/narzedzia/date-picker
//last update 15-11-2006
function Calendar(T,E,i,j,tE,tBody,Row,f,t,d,wd){
    if(!document.getElementById||!document.body.appendChild)return
    T=this
    function cEl(t,p,h,w){
        p.appendChild(t=document.createElement(t))
        if(h)t.innerHTML=h
        if(w)t.colSpan=5
        return t
        }
    function cB(x){
        with(T.Cal){
            B=0;
            x==0?Y--:x==1?Y++:x==2?(!M?(M=11,Y--):M--):(M==11?(M=0,Y++):M++)
            }
        }
if(!T.Cal){
    E=document.createElement('ins')
    E.className='clndr'
    T.parentNode.insertBefore(E,T.nextSibling)
    T.Cal={
        E:E,
        B:1,
        cD:new Date().getUTCDate(),
        cM:new Date().getMonth(),
        cY:new Date().getFullYear(),
        sD:0,
        sM:-1,
        sY:0,
        M:-1,
        Y:0
    }
    if((i=T.value.match(/\d{2,4}/g))&&i.length==3){
        with(T.Cal){
            sD=+i[0];
            sM=M=i[1]-1;
            sY=Y=i[2]
            }
        }
}
E=T.Cal.E
with(T.Cal){
    if(B){
        M=M+1?M:sM+1?sM:cM;
        Y=Y||sY||cY
        }
        f=Date.UTC(Y,M,1);
    t=Date.UTC(Y,M+1,1)
    }
while(E.childNodes[0])E.removeChild(E.firstChild)
tE=cEl('table',E)
tBody=cEl('thead',tE)
tBody.onmouseup=function(){
    T.focus()
    }
tBody.onmousemove=function(){
    if(window.getSelection)window.getSelection().removeAllRanges()
        }
Row=cEl('tr',tBody)
cEl('td',Row,'«').onmousedown=function(){
    cB(0)
    }
cEl('th',Row,T.Cal.Y,1)
cEl('td',Row,'»').onmousedown=function(){
    cB(1)
    }
Row=cEl('tr',tBody)
cEl('td',Row,'«').onmousedown=function(){
    cB(2)
    }
cEl('th',Row,cld_BlaTek.month[T.Cal.M],1)
cEl('td',Row,'»').onmousedown=function(){
    cB(3)
    }
tBody=cEl('tbody',tE)
Row=cEl('tr',tBody)
for(i=0;i<7;i++){
    cEl('th',Row,cld_BlaTek.day[i]).className='day'+(i+1)%7
    }
for(i=f;i<t;i+=86400000){
    with(new Date(i)){
        d=getUTCDate();
        wd=getUTCDay()
        }
    if(wd==1||i==f)Row=cEl('tr',tBody)
    if(wd!=1&&d==1){
        for(j=1;j<(wd?wd:7);j++)cEl('td',Row).className='empty day'+j
            }
    (tE=cEl('td',Row,d)).className='day'+wd
    tE.onmousedown=function(x){
        x=+this.innerHTML
        with(T.Cal){
            sD=x;
            sM=M;
            sY=Y;
            T.value=(x<10?'0'+x:x)+'-'+((x=M+1)<10?'0'+x:x)+'-'+Y
            // edit vadatajs
           

            }
        }
with(T.Cal){
    if(d==cD&&M==cM&&Y==cY)tE.className+=' today';
    if(d==sD&&M==sM&&Y==sY)tE.className+=' selected'
        }
    }
for(i=wd||7;i<7;){
    cEl('td',Row).className='empty day'+(++i%7)
    }
T.onblur=function(){
    if(T.Cal.B)E.className='clndr hide';
    T.form.className=T.form.className.replace(/\bhideSel\b/,'')
    }
T.Cal.B=1
E.className='clndr'
T.form.className+=' hideSel'
}


//global object (You can translate month&day names)
cld_BlaTek={
    day:['pn','wt','śr','cz','pt','so','n'],
    month:['styczeń','luty','marzec','kwiecień„','maj','czerwiec',
    'lipiec','sierpień','wrzesień','październik','listopad','grudzień']
}

//this function change days displayed in the input field
//x - number of days to add to input field
function changeDay(x,T,d){
    T=gId(T)
    if((i=T.value.match(/\d{1,4}/g))&&i.length==3){
        x=new Date(Date.UTC(1*i[2],i[1]-1,1*i[0],0,0,0)+(0x5265C00*x))
        T.value=((d=x.getUTCDate())<10?'0'+d:d)+'-'+((d=x.getMonth()+1)<10?'0'+d:d)+'-'+x.getFullYear()
        }
    }

//this function add onfocus event listener to input fields
function addCalendar(a,i){
    aEL(window,'load',function(){
        for(j in a){
            if(i=document.getElementById(a[j]))aEL(i,'focus',Calendar)
                }
            })
}

function aEL(o,t,f){
    var a=[].slice.call(arguments,3)
    o[t+f]=function(e){
        return !1===f.apply(o,[e||window.event].concat(a))?e.preventDefault?e.preventDefault():!1:1
        }
    return(o.x=o.addEventListener)?o.x(t,o[t+f],!1):(o.x=o.attachEvent)?o.x('on'+t,o[t+f]):!1
    }
function gId(i){
    return document.getElementById(i)
    }

//below line activates calendar on input fields with id: to, from, today
addCalendar(['to','from','today'])