c# 调用oracle package问题

function sendsms(
id       varchar2,
pd varchar2,
m varchar2,
sm  date,
msg in out nocopy varchar2
) return int;

 OracleConnection conn = new OracleConnection("");
            conn.Open();
            OracleCommand cmd = new OracleCommand("sendsms", conn);
            cmd.CommandType = CommandType.StoredProcedure;

            OracleParameter p1 = new OracleParameter("id", OracleType.VarChar, 100);
            p1.Direction = ParameterDirection.Input;
            p1.Value = id;

            OracleParameter p4 = new OracleParameter("pd", OracleType.VarChar, 100);
            p4.Direction = ParameterDirection.Input;
            p4.Value = password;

            OracleParameter p2 = new OracleParameter("m", OracleType.VarChar, 100);
            p2.Direction = ParameterDirection.Input;
            p2.Value = mobile;

            OracleParameter p3 = new OracleParameter("sm", OracleType.DateTime, 100);
            p3.Direction = ParameterDirection.Input;
            p3.Value = sendTime;

            OracleParameter p5 = new OracleParameter("oid", OracleType.VarChar, 100);
            p5.Direction = ParameterDirection.Input;
            p5.Value = operatorid;

            OracleParameter p6 = new OracleParameter("msg", OracleType.VarChar, 100);
            p6.Direction = ParameterDirection.InputOutput;
            p6.Value = msg;
            cmd.Parameters.Add(p1);
            cmd.Parameters.Add(p2);
            cmd.Parameters.Add(p3);
            cmd.Parameters.Add(p4);
            cmd.Parameters.Add(p5);
            cmd.Parameters.Add(p6);

            cmd.ExecuteNonQuery();

提示:PLS-00306: wrong number or types of arguments in call to 'sendsms'

以前没有调用过oracle，大家帮我看下
[最优解释]
OracleParameter p1 = new OracleParameter(":id", OracleType.VarChar, 100);