var imgsInBanner = new Array("images/SiteImgs/Headers/Header1.jpg", "images/SiteImgs/Headers/Header2.jpg", "images/SiteImgs/Headers/Header7.jpg", "images/SiteImgs/Headers/Header4.jpg", "images/SiteImgs/Headers/Header5.jpg", "images/SiteImgs/Headers/Header6.jpg");
var imgsInBannerAdmin = new Array("../images/SiteImgs/Headers/Header1.jpg", "../images/SiteImgs/Headers/Header2.jpg", "../images/SiteImgs/Headers/Header7.jpg", "../images/SiteImgs/Headers/Header4.jpg", "../images/SiteImgs/Headers/Header5.jpg", "../images/SiteImgs/Headers/Header6.jpg");
var numberOfBanners = 6;


/**
 * Darkens the given button by loading a different image.
 * @param {Object} obj Button to be changed
 */
function doEfect(obj){
    try {
        obj.style.backgroundImage = "none";
        obj.style.backgroundImage = "url(images/SiteImgs/Buttons/ButtonBackgroundGreenDark.gif)";
        obj.style.color = "#D2FBFF";
    } 
    catch (err) {
        window.alert(err);
    }
}

/**
 * Resets the state of the given button.
 * @param {Object} obj Button to be reset.
 */
function endEfect(obj){
    try {
        obj.style.backgroundImage = "url(images/SiteImgs/Buttons/ButtonBackgroundGreenClear.gif)";
        obj.style.color = "#004148";
    } 
    catch (err) {
        window.alert(err);
    }
}

/**
 * Restores swaped image.
 */
function MM_swapImgRestore(){
    var i, x, a = document.MM_sr;
    for (i = 0; a && (i < eval(a.length)) && (x = a[i]) && x.oSrc; i++) {
        x.src = x.oSrc;
    }
}

/**
 * Preload swapable images.
 */
function MM_preloadImages(){
    var d = document;
    if (d.images) {
        if (!d.MM_p) 
            d.MM_p = new Array();
        var i, j = d.MM_p.length, a = MM_preloadImages.arguments;
        for (i = 0; i < a.length; i++) 
            if (a[i].indexOf("#") != 0) {
                d.MM_p[j] = new Image;
                d.MM_p[j++].src = a[i];
            }
    }
}

/**
 * Used for swapable images.ss
 * @param {Object} n
 * @param {Object} d
 */
function MM_findObj(n, d){
    var p, i, x;
    if (!d) 
        d = document;
    if ((p = n.indexOf("?")) > 0 && parent.frames.length) {
        d = parent.frames[n.substring(p + 1)].document;
        n = n.substring(0, p);
    }
    if (!(x = d[n]) && d.all) 
        x = d.all[n];
    for (i = 0; !x && i < d.forms.length; i++) 
        x = d.forms[i][n];
    for (i = 0; !x && d.layers && i < d.layers.length; i++) 
        x = MM_findObj(n, d.layers[i].document);
    if (!x && d.getElementById) 
        x = d.getElementById(n);
    return x;
}

/**
 * Swaps an image.
 */
function MM_swapImage(){
    var i, j = 0, x, a = MM_swapImage.arguments;
    document.MM_sr = new Array;
    for (i = 0; i < (a.length - 2); i += 3) 
        if ((x = MM_findObj(a[i])) != null) {
            document.MM_sr[j++] = x;
            if (!x.oSrc) 
                x.oSrc = x.src;
            x.src = a[i + 2];
        }
}

function changeHeaderImage(){
	$('bannerImage').src = getSmallBanner(imgsInBanner[Math.floor(Math.random()*numberOfBanners)]);
}

function changeHeaderImageAdmin(){
	$('bannerImage').src = getSmallBanner(imgsInBannerAdmin[Math.floor(Math.random()*numberOfBanners)]);
}


/**
 * Loads the content of a sub-page.
 * @param {Object} url
 */
function goSubpage(url){
    //load subpage
	location.href = url;
}

/**
 * Loads the image identified by the given index as the new banner.
 * @param {Object} imageIndex
 */
function replaceHeaderImage(imageIndex){
    $('bannerImage').src = imgsInBanner[imageIndex];
}

/**
 * Given the name of a big banner, returns the name of the small version
 * of that banner.
 * @param {Object} bigBannerPath path to the big banner.
 */
function getSmallBanner(bigBannerPath){
    var x = new String(bigBannerPath);
    return x.substr(0, x.lastIndexOf('.')).concat('0', x.substr(x.lastIndexOf('.'), x.length));
}