The reference to entity “foo” must end with the &#

Question

I have Google checkout sandbox generated HTML code which works fine in HTML page. When I put the same code in XHTML page, it throws the below exception:

the reference to entity "w" must end with the ';' delimiter

It's referring the request parameter w in the URL in the below src attribute:

<input type="image" name="Google Checkout" alt="Fast checkout through Google"
    src="http://sandbox.google.com/checkout/buttons/checkout.gif?merchant_id=211512493599623&w=180&h=46&style=white&variant=text&loc=en_US"
    height="46" width="180" />

How is this caused and how can I solve it?

Answer 1

The ampersand & is a special character in HTML and XML. If you want to use it as a normal character, you have to encode it correctly. Write & instead of &:

src="...9623&w=180&h=46&style=white&variant=text&loc=en_US"

& denotes the start of an encoded entity, such as < for <, or & for &. In your case the parser tries to interpret &w as an entity. But entities are always terminated by an ;, thus if the ; is missing you get the error message.