// get 1st index
var intImgIndex = rand2(4);  

// write HTML for 1st image, with enclosing <a>, alt text, and caption as defined above
document.write('<div id="feature"><a href="' + aryImageItems[intImgIndex].url + '"><img src="images/' + aryImageItems[intImgIndex].imagefilename + '.gif" width="900" height="598" border="0" alt="' + aryImageItems[intImgIndex].caption +'" /></a>');