error in API

Hi

Gurus

my idea is to run a DM package with a click of the button

I followed certain links in the forum help and tried to run a DM package with the macro below

but i could not solve the error

Compile error:

Argument not optional

below is the macro

Dim EPM As New FPMXLClient.EPMAddInAutomation

Sub RUN()

EPM.DataManagerRunPackage "Periodic_abc", "RFcst", ""

End Sub

where Periodic_abc is the Pacakge

and Pacakge group is RFcst

this is the link i followed

VBA Error - unable to run package from VBA using EPM 10 API

thanks