function ChangeAtImage(currentpage) {
	
	    // (1) Clear all images
			
	    // create an array of image names for the navbar
	    var buttons = ['Title', 'Preface', 'Contents', 'Abstract', 'Spotlight', 'Chapter1', 'Chapter2', 'Chapter3', 'Chapter4', 'Chapter5', 'Chapter6', 'References', 'Appendices'];

			for( i=0 ; i<buttons.length ; i++ ) { // Loop through each image object in the navbar
			    var imagename = buttons[i]; //assign current image name to a temp variable
					parent.frames[0].document.images[imagename].src = "./images/nav" + imagename + ".gif";  //reset all images to normal
			}
			
			// (2) Set the image we are at to the *At* image
	    parent.frames[0].document.images[currentpage].src = "./images/nav" + currentpage + "At.gif";  
	}