Adds a user to another user's friends list in a specific sub directory. 

This method can be accessed through the Friends.asmx file located in:

~/Workarea/webservices/WebServiceAPI/Community/Friends.asmx

[SoapHeader("AuthHeader")]
[SoapHeader("RequestInfoHeader")]
[WebMethod(MessageName = "AddFriend for directory", Description = "Adds a user to aother user's friends list in a specific sub directory.")]
public void AddFriend(long friendUserId, long userId, long directoryId);

<SoapHeader("AuthHeader")>
<SoapHeader("RequestInfoHeader")>
<WebMethod(MessageName = "AddFriend for directory", Description = "Adds a user to aother user's friends list in a specific sub directory.")>
Public Function AddFriend(friendUserId As long, userId As long, directoryId As long) As void