var elmImg = document.getElementById("featuredPrizeImg");
var elmLnk = document.getElementById("featuredPrizelnk");
var elmDsc = document.getElementById("prizeDescription");
var opacNum;
var curPrzIdx = 0;
opacTimer = setInterval(changePrize, 1250);            
function fadeIn() {
    opacNum += 2;
    changeOpac(elmDsc, opacNum);    
    changeOpac(elmImg, opacNum);    
    if (opacNum >= 100) {
        clearInterval(opacTimer);
        opacTimer = setInterval(changePrize, 1250);            
    }
}
function fadeOut() {
    opacNum -= 2;
    changeOpac(elmDsc, opacNum);    
    changeOpac(elmImg, opacNum);    
    if (opacNum <= 0) {
        clearInterval(opacTimer);
        curPrzIdx = (curPrzIdx+1 < ftrdIds.length ? curPrzIdx += 1 : 0);
        elmImg.src = "/images/swag-bucks/thumb" + ftrdIds[curPrzIdx] + "." + ftrdExt[curPrzIdx];
        elmLnk.href = "/?cmd=sb-checkout&id=" + ftrdIds[curPrzIdx];
        elmDsc.innerHTML = ftrdDsc[curPrzIdx];
        opacTimer = setInterval(fadeIn, 20);            
    }
}

function changePrize() {
    opacNum = 100;
    clearInterval(opacTimer);
    opacTimer = setInterval(fadeOut, 20);
}
function changeOpac(elm, opacity) {
    elm.style.opacity = (opacity / 100);
  	elm.style.MozOpacity = (opacity / 100);
  	elm.style.KhtmlOpacity = (opacity / 100);
  	elm.style.filter = "alpha(opacity=" + opacity + ")";
}