Michel,

As Bonnie mentioned in an earlier thread you could also declare the function as shared (refered to as static in C#). Since your class does not appear to contain a "Sub New()" constructor (ie, requires no initialization of parameters, objects etc. to be used) then there is no need for you to instanciate it before calling any functions. Simply add the "shared" keyword to your function declaration.

Public Shared Function AddSpeaker(ByVal tnSpeakerID, ByVal tlPicture, ByVal tcName, ByVal tmBio) As String

You should then be able to reference the function directly using ClassName.FunctionName

_Function.AddSpeaker