NewImg = new Array('file1.jpg','file2.jpg','file3.jpg','file4.jpg');
//Starting image is Selected
var StartFile = 'file3.jpg';
var ImgNum;
for(i in NewImg) {
	File = NewImg[i].split('/');
	File = File.pop();
	if(File == StartFile) {
		ImgNum = i;
		break;
	}
}

var ImgLength = NewImg.length - 1;
function chgImg(direction) {
	if (document.images) {
		ImgNum = ImgNum + direction;

		if (ImgNum > ImgLength) {
			ImgNum = 0;
		}
		if (ImgNum < 0) {
			ImgNum = ImgLength;
		}
		document.imageviewer.src = NewImg[ImgNum];
  	 }
}
//
</script>

<div id="holder" align="center" style="width:100%;">
<script language="javascript">
document.write('<img src="'+NewImg[ImgNum]+'" name="imageviewer" border="0" />');
</script>
</div>
<div align="center" style="width:100%;">
<a href="javascript:chgImg(-1)">Previous Detail</a> &brvbar; <a href="javascript:window.close();">Close Window</a> &brvbar; <a href="javascript:chgImg(1)">Next Detail</a></div>