function change_image(src, width, height)
{
	mainimage.src="images/products/" + src;
	mainimage.width=width;
	mainimage.height=height;
}

function show_img(product_id, width, height)
{
   var a
   var b
   var url
   vidWindowWidth=width;
   vidWindowHeight=height;
   a=(screen.height-vidWindowHeight)/5;
   b=(screen.width-vidWindowWidth)/2;
   features="top="+a+",left="+b+",width="+vidWindowWidth+",height="+vidWindowHeight+",toolbar=no,menubar=no,location=no,directories=no,scrollbars=no,resizable=no";
   url="photo.php?product_id="+product_id;
   window.open(url,'',features,true);
}