function img_swap(time1, time2){

// À̹ÌÁöÀÇ ³ëµå¸®½ºÆ®¸¦ ³Ñ°Ü¼­ À̹ÌÁö¸¦ ÀüȯÇÏ´Â ÇÔ¼ö¸¦ µ¹·ÁÁִ Ŭ·¡½ºÇ³ÀÇ ÇÔ¼ö
var ChangeElementInterval = function(nodeList) {

var s = document.body.style;
// Åõ¸íµµÀÇ ¼³Á¤ÇÏ´Â ÇÔ¼ö
// elem: Åõ¸íµµ¸¦ ¼³Á¤ÇÏ´Â ¿ä¼Ò
// opacity: Åõ¸íµµ[%]
var setOpacity =
s.opacity !== undefined ? function(elem, opacity) { elem.style.opacity = opacity / 100; }:
s.filter !== undefined ? function(elem, opacity) { elem.style.filter = 'alpha(opacity=' + opacity + ')'; }:
function(elem, opacity) { elem.style.MozOpacity = opacity / 100; };

// À̹ÌÁöÀÇ ¿ä¼Ò¸¦ Ãëµæ
// ºñÇ¥½Ã¿ä¼Ò¿¡ opacity=0À» ¼³Á¤ÇÏ´Â ·çÇÁ
for (var i = 0; i < nodeList.length; i++) {
// .style.display == nullÀº ±¸SafariÀÇ bug´ëÀÀ
if (nodeList[i].style.display == 'none' || nodeList[i].style.display == null) setOpacity(nodeList[i], 0);
// Ç¥½Ã¿ä¼ÒÀÇ ¹øÈ£
else var index = i;
}

// Åõ¸íµµ¸¦ º¯°æÇØ°¡´Â ÇÔ¼ö
// elem: Ÿ°Ù¿ä¼Ò
// from: ½ÃÀÛÅõ¸íµµ
// to: Á¾·áÅõ¸íµµ
// time: Àüȯ½Ã°£[ms]
// callback: Á¾·áÈÄ ½ÇÇàÇÒ ÇÔ¼ö
var changeOpacity = function(elem, from, to, time, callback) {
// Åõ¸íµµÀÇ º¯°æÀ» ÇÏ´Â ÇÔ¼ö¸¦¸¦ È£ÃâÇÏ´Â Interval
var interval = 80;
var curr = from;
var step = (to - from) * interval / time;
(function () {
var c = Math.round(curr += step);
setOpacity(elem, c);
if(c != to) {
if ((curr + step - to) * (curr - to) < 0) step = to - curr;
setTimeout(arguments.callee, interval);
}
else if (callback) callback.call(elem, to);
})();
};

// Ç¥½Ã¸¦ ÀüȯÇÏ´Â ÇÔ¼ö,changeOpacity¸¦ È£ÃâÇÑ´Ù
// from: ÀüȯÀüÀÇ ¿ä¼Ò
// to: Àüȯ ÇÒ ¿ä¼Ò
// time: Àüȯ ½Ã°£
var changeElem = function(from, to, time) {
if (to.style.removeProperty) to.style.removeProperty('display');
else to.style.display = ''; /* for IE */
changeOpacity(from, 100, 0, time, function() { this.style.display = 'none'; });
changeOpacity(to, 0, 100, time);
};

// À̹ÌÁö¸¦ ÀÏÁ¤°£°ÝÀ¸·Î ÀüȯÇÏ´Â ÇÔ¼ö¸¦ ¹Ýȯ
// interval: À̹ÌÁöÀÇ Ç¥½Ã½Ã°£[ms]
// time: Àüȯ ½Ã°£[ms]
return function(interval, time, callback) {
setTimeout(function() {
changeElem(nodeList[index], nodeList[++index >= nodeList.length ? (index = 0) : index], time);
changeImgInterval(interval, time)
}, interval);
};
};

// Àμö·Î À̹ÌÁöÀÇ nodeList¸¦ ³Ñ±â¸é, ÀüȯÇÔ¼ö°¡ ¹ÝȯµÈ´Ù
var changeImgInterval = ChangeElementInterval(document.getElementById('img-wrapper').getElementsByTagName('img'));

// 5ÃÊ °£°ÝÀ¸·Î À̹ÌÁö¸¦ ÀüȯÇÏ°í, 1ÃʷΠǥ½Ã¸¦ ÀüȯÇÑ´Ù.
changeImgInterval(time1, time2);
};