document.byId = function(strId) {
    if (document.getElementById)
        return document.getElementById(strId);
    else if (document.all)
        return document.all[strId];
    else if (document[strId])
        return document[strId];
    else if (document.layers && document.layers[strId])
        return document.layers[strId];
}

if (String && String.prototype) {
    String.prototype.trim = function() {
        return this.replace(/^\s+|\s+$/g, "");
    }
}

function swapImage(imgObj, strImg) {
    imgObj.old = imgObj.src;
    imgObj.src = strImg;
}

function restoreImage(imgObj) {
    imgObj.src = imgObj.old;
}

function swapBkSglImage(obId, imgId) {
    var obHtml = document.byId(obId);
    var obCacheImg = document.byId("photo" + imgId);
    var imgUrl = obCacheImg.src;//SGL_JS_WEBROOT + "/media/file/action/previewMedia/frmMediaId/" + imgId + "/file_name/" + imgId + ".jpg";
    if (obHtml) {
        if (obHtml.src)
            obHtml.src = imgUrl;
        else
            obHtml.style.backgroundImage = "url(" + imgUrl + ")";
    }
}

function doFade(obImage, targetOpacity) {

    var nextOpacity = obImage.currentOpacity + obImage.nFadeStep;
    if (obImage.nFadeStep > 0 && nextOpacity > targetOpacity)
        nextOpacity = targetOpacity;
    else if (obImage.nFadeStep < 0 && nextOpacity < targetOpacity)
        nextOpacity = targetOpacity;

    if (nextOpacity == targetOpacity) {
        clearInterval(obImage.filterTimer);
        obImage.filterTimer = null;
    }

    if (obImage.filters && obImage.filters[0]) {
        obImage.filters[0].opacity = nextOpacity;
    }
    else {
        obImage.style.opacity = (nextOpacity / 100);
    }
    obImage.currentOpacity = nextOpacity;
}

function fadeImage(obImage, nOpacity, nTimer) {
    if (obImage.filterTimer) {
        clearInterval(obImage.filterTimer);
        obImage.filterTimer = null;
    }

    var nCurrent = 75;
    if (obImage.currentOpacity)
        nCurrent = obImage.currentOpacity;
    obImage.currentOpacity = nCurrent;

    var nStep = Math.round((nOpacity - nCurrent) / 7);
    var nInterval = Math.round(nTimer / 7);

    obImage.nFadeStep = nStep;

    obImage.filterTimer = setInterval(function() { doFade(obImage, nOpacity); }, nInterval);
}

var __g_strOldTabId = "tabOne";
var __g_strOldDivId = "featureTabOne";

function changeToTab(strTabId, strDivId) {

    var obTab = document.byId(strTabId);
    var obDiv = document.byId(strDivId);

    var obOldTab = document.byId(__g_strOldTabId);
    var obOldDiv = document.byId(__g_strOldDivId);

    if (!obTab || !obDiv || !obOldTab || !obOldDiv)
        return;

    obOldTab.className = "";
    obOldDiv.className = "homeFeatureInactive";

    obTab.className = "tabActive";
    obDiv.className = "homeFeatureActive";

    __g_strOldTabId = strTabId;
    __g_strOldDivId = strDivId;
}