Sum of Doctotal in Draft Sales Order in ORDF

Hi,

Asking for your help, i dont know whats wrong with this script i new with regards to creating a script guys,

all i want is to view the Sum of Doctotal of all Draft Documents with Docstatus is Open with particular Business partner

here is the script

SELECT ( SUM(T1.DocTotal)) FROM OCRD T0 INNER JOIN ODRF T1 ON T0.CardCode = T1.CardCode AND T1.DocStatus ='O' WHERE  T0.CardCode=$[$4.0.0]

thank you in advance

silent