Web question - load local asset bundle (without knowing URL)

Unity Engine
1

So I have a web page with Unity3D files. One unity3D file streams in data from another unity3D assetbundle.
It seems I can’t just call
var www = WWW(“assetbundle.unity3d”)
as a full URL is needed not a relative one - correct?
Can i get the current web address somehow so I can construct the full URL? (I do not want to hard code the full URL at this point)

2