Here is my (relevant) css code:

```
li a {
  display: block;
  font-weight:bolder;
  color: #000;
  padding: 8px 16px;
  text-decoration: none;
  background-image: url('004.jpg')
}

/* Change the link color on hover */
li a:hover {
  background-color: #555;
  color: white;
}

```

I've tried the URL with double quotes, single quotes, and no quotes and it still isn't working. Can someone help me with this?

Thanks so much for your wise advice.