function displayImage(index){

	//display the image
	document.getElementById('product_image_display').src = imagesArray[index];

	//change the style of the links
	document.getElementById('link_0').className = 'img_inactive';
	document.getElementById('link_1').className = 'img_inactive';
	if(imagesArray.length == 3){
		document.getElementById('link_2').className = 'img_inactive';
	}
	document.getElementById('link_'+index).className = 'img_active';
}