I have this method to add a namespace from my XML class:

    ' Add a namespace
    Public Function AddNamespace() As Boolean
        Dim lcNamespace As String = ""
        Dim lcUri As String = ""
        Dim llSuccess As Boolean = False

        ' Reset the values
        cMessage = ""

        ' Initialization
        lcNamespace = Trim(cNamespace)
        lcUri = Trim(cUri)

        ' If we have a Uri
        If lcUri.Length > 0 Then

            ' If we have a namespace
            If lcNamespace.Length > 0 Then

                Try

                    ' Create the XmlNameSpaceManager object once
                    ' This is needed as we could add several namespaces
                    If oXmlNameSpaceManager Is Nothing Then
                        oXmlNameSpaceManager = New XmlNamespaceManager(oXmlDocument.NameTable)
                    End If

                    oXmlNameSpaceManager.AddNamespace(lcNamespace, lcUri)
                    llSuccess = True
                Catch loException As Exception
                    cMessage = loException.Message
                End Try

            Else
                cMessage = cYouNeedToDefineTheNamespaceProperty
            End If
        Else
            cMessage = cYouNeedToDefineTheUriProperty
        End If

        ' Reset the values
        cNamespace = ""
        cUri = ""

        Return llSuccess
    End Function

However, I just found out that even if the namespace does not exist, this will not go in the Catch as an exception.

I would like to make an adjustment that if the namespace does not exist, that it will go in the exception.

Is there a way to verify if a namespace exists?