ASP.NET and Oracle Database 11g

Hi,

I am using oracle database 11g as back end and vb.net using as front end in my web based application framework version 4.0.

I have created a function in Oracle which used to return a RefCursor and I am trying to get the value of that RefCursor in my vb.net coding and getting the following error:

ORA-06550: line 1, column 15:
PLS-00306: wrong number or types of arguments in call to 'FN_FLEET_REPORT_TEST'
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored

my code where I am calling the oracle function is:

                        Dim cmd As New OracleCommand

			cmd.Connection = DBCon
			cmd.CommandText = <myfunctionname>
			cmd.CommandType = CommandType.StoredProcedure

			cmd.Parameters.Add(New OracleParameter("v_loginname", OracleDbType.Varchar2)).Value = pLoginName
			cmd.Parameters.Add(New OracleParameter("sdate", OracleDbType.Varchar2)).Value = pStartDate
			cmd.Parameters.Add(New OracleParameter("edate", OracleDbType.Varchar2)).Value = pEndDate

			cmd.Parameters.Add(New OracleParameter("c_direct_reports", OracleDbType.RefCursor)).Direction = ParameterDirection.ReturnValue

			Dim da As New OracleDataAdapter(cmd)
			da.Fill(dtData)

			Return dtData

My oracle function:

CREATE OR REPLACE FUNCTION <MYFUNCTIONNAME> (v_loginname IN varchar2,sdate IN varchar2, edate IN varchar2)


RETURN SYS_REFCURSOR


AS

  c_direct_reports SYS_REFCURSOR;

v_sql clob;

BEGIN


   v_sql :='<MYQUERY>';


dbms_output.put_line(v_sql); 

OPEN c_direct_reports FOR v_sql;

RETURN c_direct_reports;



END;
/

Please help anybody to resolve this problem, i am really stuck.