var ss_state = 0; 
	var ss_imgIdx = 0;
	var ss_intervalID; 
	var ss_targetImg; 
	var ss_onBtnCache = new Array(3);
	ss_onBtnCache["previous"] = new Image();
	ss_onBtnCache["previous"].src = "images/btn_small_back_hover.gif";
	ss_onBtnCache["play"] = new Image();
	ss_onBtnCache["play"].src = "images/btn_small_play_hover.gif";	
	ss_onBtnCache["pause"] = new Image();
	ss_onBtnCache["pause"].src = "images/btn_small_pause_hover.gif";		
	ss_onBtnCache["next"] = new Image();
	ss_onBtnCache["next"].src = "images/btn_small_next_hover.gif";
	
	var ss_offBtnCache = new Array(3);
	ss_offBtnCache["previous"] = new Image();
	ss_offBtnCache["previous"].src = "images/btn_small_back_on.gif";
	ss_offBtnCache["play"] = new Image();
	ss_offBtnCache["play"].src = "images/btn_small_play_on.gif";	
	ss_offBtnCache["pause"] = new Image();
	ss_offBtnCache["pause"].src = "images/btn_small_pause_on.gif";		
	ss_offBtnCache["next"] = new Image();
	ss_offBtnCache["next"].src = "images/btn_small_next_on.gif";
	
	function ss_btnOn(btnName)
	{
		document.images[btnName].src = ss_getBtnSrc(btnName, ss_onBtnCache);
	}
	
	function ss_btnOff(btnName)
	{
		document.images[btnName].src = ss_getBtnSrc(btnName, ss_offBtnCache);
	}
	
	function ss_getBtnSrc(btnName, btnCache)
	{
		if ("play" == btnName) 
			return 1 == ss_state ? btnCache["pause"].src : btnCache[btnName].src;
		else
			return btnCache[btnName].src;
	}	
	
	function ss_init()
	{
		ss_targetImg = document.images["ss_target_img"];
		ss_targetImg.src = ss_imgCache[ss_imgIdx].src;
		ss_cacheNextImg();
		ss_cachePrevImg();
		
		
		ss_play();
		ss_btnOff("play");
		
	}

	function ss_play()
	{
		if (1 == ss_state) 
		{
			ss_state = 0;
			document.images["play"].alt = "Play";
			clearInterval(ss_intervalID);
		}
		else
		{
			ss_state = 1;
			document.images["play"].alt = "Pause";
			ss_intervalID = setInterval("ss_transNextImg()", 2000);
		}
		ss_btnOn("play");
	}
	
	function ss_prev()
	{
		if (1 == ss_state) 
		{
			ss_state = 0;
			clearInterval(ss_intervalID);	
			ss_targetImg.src = ss_imgCache[ss_getPrevIdx()].src;
			ss_cachePrevImg();
			ss_play();
			ss_btnOff("play");			
		}
		else
		{
			ss_targetImg.src = ss_imgCache[ss_getPrevIdx()].src;
			ss_cachePrevImg();		
		}		
	}
	
	function ss_next()
	{
		if (1 == ss_state) 
		{
			ss_state = 0;
			clearInterval(ss_intervalID);	
			ss_targetImg.src = ss_imgCache[ss_getNextIdx()].src;
			ss_cacheNextImg();
			ss_play();
			ss_btnOff("play");			
		}
		else
		{
			ss_targetImg.src = ss_imgCache[ss_getNextIdx()].src;
			ss_cacheNextImg();		
		}
	}

	function ss_transNextImg()
	{
		
		ss_targetImg.src = ss_imgCache[ss_getNextIdx()].src;
		
		ss_cacheNextImg();		
	}
	
	function ss_getNextIdx()
	{
		ss_imgIdx++;
		if (ss_imgIdx == ss_rgsImgURL.length)
			ss_imgIdx = 0;
		return ss_imgIdx;
	}
	
	function ss_getPrevIdx()
	{
		if (ss_imgIdx == 0)
			ss_imgIdx = ss_rgsImgURL.length - 1;
		else
			ss_imgIdx--;
		return ss_imgIdx;
	}	
	
	function ss_cacheNextImg()
	{
		var imgIdx = ss_imgIdx + 3;
		if (imgIdx != ss_imgCache.length && null == ss_imgCache[imgIdx])
			ss_cacheImg(imgIdx)
	}
	
	function ss_cachePrevImg()
	{
		var imgIdx = (0 == ss_imgIdx) ? ss_rgsImgURL.length - 1 : ss_imgIdx - 1;
		if (null == ss_imgCache[imgIdx])
			ss_cacheImg(imgIdx)
	}
	
	function ss_cacheImg(idx)
	{
		ss_imgCache[idx] = new Image();
		ss_imgCache[idx].src = ss_rgsImgURL[idx];
	}