function preloadImages(preloadAry)
{
     // counter
     var i = 0;
     // create object
     var imageObj = new Image();
     // start preloading
     for(i=0; i<=3; i++) 
     {
          imageObj.src=preloadAry[i];
     }
     imageObj = null;
}
function setBannerImage(idx)
{
    var bannerImage = document.getElementById("bannerImage");
    bannerImage.src = bannerAry[idx]; 
    var bannerHref = document.getElementById("bannerHref");
    bannerHref.href = linkAry[idx];
    
    //assign the image map name to the image if it is not empty
    var mapName = mapNameAry[idx];
    if (mapName != "")
        bannerImage.useMap = "#" + mapName;
    
    if (linkAry[idx].indexOf("http") > -1 && linkAry[idx].indexOf("javascript:") == -1)
        bannerHref.target = "_blank";
    else
        bannerHref.target = "";
}
function initBanner()
{
    setBannerImage(curBannerIdx);
    if (timerId > 0)
        window.clearInterval(timerId);    
    timerId = window.setInterval(rotateBanner, 8000);
}
function rotateBanner()
{   
    if (curBannerIdx + 1 < bannerAry.length)
        curBannerIdx++;
    else
        curBannerIdx = 0;
         
    setBannerImage(curBannerIdx);
}
function forwardBanner()
{
    if (timerId > 0)
        window.clearInterval(timerId);

    rotateBanner();
    var pausePlayImage = document.getElementById("pausePlayImage");
    pausePlayImage.src = pauseImage;    
    timerId = window.setInterval(rotateBanner, 8000);
}
function pauseBanner()
{
    if (timerId > 0)
        window.clearInterval(timerId);
}
function rewindBanner()
{
    if (timerId > 0)
        window.clearInterval(timerId);

    if (curBannerIdx == 0)
        curBannerIdx = bannerAry.length - 1;
    else
        curBannerIdx--;
    
    setBannerImage(curBannerIdx);
    var pausePlayImage = document.getElementById("pausePlayImage");
    pausePlayImage.src = pauseImage;
    timerId = window.setInterval(rotateBanner, 8000);
}
function toggleBanner(e)
{
    if (!e)
        e = event;
        
	var pausePlayImage = document.getElementById("pausePlayImage");
	if (pauseBanner && e)
	{
	    var imgElement = (e.srcElement) ? e.srcElement : e.target;
		if (imgElement.alt.indexOf("pause") > -1)
		{
				pauseBanner();
		  		pausePlayImage.src = playImage;
		  		pausePlayImage.alt = "play";			
		}
		else
		{
				initBanner();
		  		pausePlayImage.src = pauseImage;
		  		pausePlayImage.alt = "pause";
		}
	}
}