Selecting attribute values with html Agility Pack

I'm trying to retrieve a specific image from a html document, using html agility pack and this xpath:

//div[@id='topslot']/a/img/@src

As far as I can see, it finds the src-attribute, but it returns the img-tag. Why is that?

I would expect the InnerHtml/InnerText or something to be set, but both are empty strings. OuterHtml is set to the complete img-tag.

Are there any documentation for Html Agility Pack?

From stackoverflow

• Html Agility Pack does not support attribute selection.

• Html Agility Pack will support it soon.

  http://htmlagilitypack.codeplex.com/Thread/View.aspx?ThreadId=204342