/*
 *  home.js
 *
 *  Scripting functionality used on the home page.
 */

var mainImages;
var currentImageIdx;
var currentZIndex;
var currentOpacity;
var fadeTimer;

function defineImages(numImages) {

    mainImages = new Array(numImages);

    for (var i=0; i<numImages; i++) {
        mainImages[i] = new Image();
        mainImages[i].src = "/images/home_main_" + (i+1) + ".jpg";
    }

    currentImageIdx = 0;
    currentZIndex = mainImages.length;
}

function swapImage() {

    if (currentImageIdx >= mainImages.length-1) {
        currentImageIdx = 0;
    }
    else {
        currentImageIdx++;
    }

    currentOpacity = 0;
    var newImgStyle = getObject("img_main" + currentImageIdx).style;

    newImgStyle.opacity = currentOpacity;
    newImgStyle.filter = "alpha(opacity=" + currentOpacity + ")";
    newImgStyle.zIndex = ++currentZIndex;

    fadeTimer = setInterval("fadeIn(" + currentImageIdx + ")", 50);
}

function fadeIn(imgIdx) {

    currentOpacity += 10;

    var imgStyle = getObject("img_main" + currentImageIdx).style;
    imgStyle.opacity = currentOpacity / 100;
    imgStyle.filter = "alpha(opacity=" + currentOpacity + ")";

    if (currentOpacity == 100) {
        clearInterval(fadeTimer);
    }
}