ASP调用ORACLE函数的问题

函数的包头如下.
create or replace package ITOSC_ACCESS IS
FUNCTION CALLSERVICE(SerialNo varchar2,inValue in out nocopy varchar2,outValue out sys_refcursor,hint out nocopy varchar2,error out nocopy varchar2) return pls_integer

ASP调用的代码如下:
const connstr_xcjg="Provider=OraOLEDB.Oracle;Password=call0901;User ID=service;Data Source=dss;Persist Security Info=True"
dim cn
dim rs
dim cm
dim XmlHtml
dim syr
dim sfzmhm
set cn=server.CreateObject("adodb.connection")
set rs=server.CreateObject("adodb.recordset")
set cm=server.CreateObject("adodb.command")

cn.ConnectionString = connstr_xcjg
cn.open
Set cm.ActiveConnection = cn
cm.CommandType = 1
cm.commandtext = "{? = Call itosc_access.callservice(?,?,?,?)}"
cm.Parameters.Append cm.CreateParameter("l_request",3,4)
cm.Parameters.Append cm.CreateParameter("SerialNo",200,1,256,"1234567891")
cm.Parameters.Append cm.CreateParameter("inValue",200,1,256,",02,B6E228,")
cm.Parameters.Append cm.CreateParameter("hint",200,2,256)
cm.Parameters.Append cm.CreateParameter("error",200,2,256)

set rs = cm.Execute()
cn.close

错误信息:wrong number or t