var imgList = new Array() 
imgList[0] = 'images/NewLibrary.jpg'
imgList[1] = 'images/libdraft.jpg'
imgList[2] = 'images/libuser01.jpg'
imgList[3] = 'images/readingflr3.jpg'
imgList[4] = 'images/libfloor.jpg'
imgList[5] = 'images/cirdesk01.jpg'
imgList[6] = 'images/libbooks.jpg'
function showImage(){
   var imgChoice = Math.floor(Math.random() * imgList.length);
   document.write('<img src="' + imgList[imgChoice] + '" border=0 >');
}