Ok just changed the code property to :
Function ReturnXML(ByVal MultiValueList As Object, ByVal Root As String, ByVal Node As String, ByVal Element As String) As String
'**************************************************************************
' Returns an XML string by using the specified values.
' Parameters:
' MultiValueList - a multi value list from SSRS
' Root, Node, Element - String to use in building the XML string
'**************************************************************************
Dim ReturnString = ""
Dim sParamItem As Object
ReturnString = " "
For Each sParamItem In MultiValueList
ReturnString &= " "
Next
ReturnString &= " "
Return (ReturnString)
End Function
now my error is 'parameter '@C' contains an error: [] Name ReturnXML is not declared.
My dataset Parameter code is: =ReturnXML(Parameters!C.Value,"C","Customer","Customer_Number") - C being the name of the multivalue parameter which is defined as string the the parameter details.