var starblink=450;  // LENGTH OF TIME STARS TWINKLE ON IN MILLISECONDS
var stardelay=4;    // DELAY BETWEEN TWINKLES IN SECONDS
var fadedelay = 200;    // LENGTH OF FADE DELAY

var w3c=(document.getElementById)?true:false;
var ie4=(document.all && !w3c)?true:false;
var ie5=(document.all && w3c)?true:false;

var windowW, windowH,star;

function getwindowdims(){
    windowW=(ie4||ie5)? document.body.clientWidth: window.innerWidth;
    windowH=(ie4||ie5)?  document.body.clientHeight :window.innerHeight;
}

function twinkle(phs,c){
    var x,y;
    if(phs==2){
        x=Math.floor(Math.random()*windowW-80);
        y=Math.floor(Math.random()*windowH-80);

        star.style.visibility="visible";
        star.style.left=x+'px';
        star.style.top = y + 'px';
        shiftOpacity(star.id);

        setTimeout('twinkle(1,' + (Math.floor(Math.random())) + ')', starblink);
    } else {
        star.style.visibility = "visible";
        shiftOpacity(star.id);
        setTimeout('twinkle(2,' + c + ')', stardelay);
    }
}

document.write('<img id="star" src="/templates/korol3/images/star.gif" style="position:absolute; width:26px; height:24px; top:0px; left:0px; visibility:hidden" />');

window.onload=function(){
    star=(document.getElementById('star'));
    getwindowdims();
    window.onresize=getwindowdims;
    twinkle(2,0);
}


// FADE EFFECT

function shiftOpacity(id) {
    //if an element is invisible, make it visible, else make it ivisible 
    if (document.getElementById(id).style.opacity == 0) {
        opacity(id, 0, 100, fadedelay);
    } else {
        opacity(id, 100, 0, fadedelay);
    }
} 

function opacity(id, opacStart, opacEnd, fadedelay) {
    //speed for each frame
    var speed = Math.round(fadedelay / 100);
    var timer = 0;

    //determine the direction for the blending, if start and end are the same nothing happens 
    if (opacStart > opacEnd) {
        for (i = opacStart; i >= opacEnd; i--) {
            setTimeout("changeOpac(" + i + ",'" + id + "')", (timer * speed));
            timer++;
        }
    } else if (opacStart < opacEnd) {
        for (i = opacStart; i <= opacEnd; i++) {
            setTimeout("changeOpac(" + i + ",'" + id + "')", (timer * speed));
            timer++;
        }
    }
}

//change the opacity for different browsers 
function changeOpac(opacity, id) {
    var object = document.getElementById(id).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
}