C#调用ORACLE包中的存储过程报错

过程定议：
   PROCEDURE P_LOGI(iv_userid IN VARCHAR,iv_password IN VARCHAR,
                    ov_username OUT VARCHAR,ov_role OUT VARCHAR)
  IS
    r_zy JC_ZHIYDOC%ROWTYPE;
  BEGIN
    BEGIN
      SELECT * INTO r_zy
        FROM JC_ZHIYDOC
       WHERE ZHIY_NO=Upper(iv_userid);
    EXCEPTION WHEN OTHERS THEN
      PRC_UTL_RAISE(-20011,'WXW.P_LOGI','HDL001','@USER='||iv_userid||';');
    END;    IF r_zy.PWD IS NULL THEN
      PRC_UTL_RAISE(-20011,'WXW.P_LOGI','HDL003','');
    END IF; /*  \* IF Upper(iv_password)<>F_DECRYPT_DATA(r_zy.PWD) THEN
      PRC_UTL_RAISE(-20011,'PKG_UTL_LOGIN.P_LOGIN','HDL002','');*\
    END IF;*/    ov_username := r_zy.ZHIY_NAME;
    ov_role     := r_zy.JIAOS_ID;
  END P_LOGI;
C#前台调用：
 private void button1_Click(object sender, EventArgs e)
        {
            //声明变量
            string iv_userid = "";
            string iv_password = "";
            string ov_username = "";
            string ov_role = "";            OracleConnection ORCNET = new OracleConnection("data source=lmis6;user id=Lmis;password=lmis6xj");
            OracleCommand cmd = new OracleCommand("WXW.P_LOGI", ORCNET);
            cmd.CommandType = CommandType.StoredProcedure;
            OracleParameter[] parm = new OracleParameter[4];
            //in
            parm[0] = new OracleParameter(@iv_userid, OracleType.VarChar, 10);
            parm[1] = new OracleParameter(@iv_password, OracleType.VarChar, 32);
            //out
            parm[2] = new OracleParameter(@ov_username, OracleType.VarChar, 50);
            parm[3] = new OracleParameter(@ov_role, OracleType.VarChar, 50);
            //设置参数输入输出类型
            parm[0].Direction=ParameterDirection.Input;
            parm[1].Direction=ParameterDirection.Input;
            parm[2].Direction=ParameterDirection.Output;
            parm[3].Direction=ParameterDirection.Output;
            //设置参数值类型
            parm[0].DbType = DbType.String;
            parm[1].DbType = DbType.String;
            parm[2].DbType = DbType.String;
            parm[3].DbType = DbType.String;
            //给参数赋值
            parm[0].Value = name.Text;
            parm[1].Value = pwd.Text;
            parm[2].Value = null;
            parm[3].Value = null;
            if (name.Text.Trim() == "" || pwd.Text.Trim() == "")
            {
                MessageBox.Show("用户名或密码不能为空！");
            }
            cmd.Parameters.Add(parm[0]);
            cmd.Parameters.Add(parm[1]);
            cmd.Parameters.Add(parm[2]);
            cmd.Parameters.Add(parm[3]);
            try
            {
                ORCNET.Open();
                cmd.ExecuteNonQuery();
                        MessageBox.Show("成功连接ORACLE数据库");
                //ORCNET.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
            finally
            {             }
        }