简单的asp.net+ORACLE的问题

我在做插入语句是遇到了问题,代码如下:
/// <summary>
        /// 添加一条记录
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        private static readonly string SQL_GET_SYSADMINNUM = "SELECT seqsysadmin.nextval FROM sysadmin";
        private static readonly string SQL_ADMIN_INSERT_INTO = "INSERT INTO sysadmin(adminid,adminname,adminpwd,issuper) values(':adminid',':adminname',':adminpwd',':issuper')";
        
        public void Add(BusManage.Model.SysAdmin model)
        {
            int id = 0;
            id = Convert.ToInt32(OracleHelper.ExecuteScalar(OracleHelper.ConnectionString, CommandType.Text, SQL_GET_SYSADMINNUM));
            model.ADMINID = id;
        
            OracleParameter[] parm=new OracleParameter[]
                {
                    new OracleParameter(":adminname",model.ADMINNAME),
                    new OracleParameter(":adminpwd",model.ADMINPWD),
                    new OracleParameter(":issuper",model.ISSUPER)
                    
                };
            //OracleParameter[] parm =
            //{
            //    new OracleParameter("adminid",OracleType.Number),
            //    new OracleParameter("adminname",OracleType.VarChar),
                 
            //    new OracleParameter("adminpwd",OracleType.VarChar),
               
            //    new OracleParameter("issuper",OracleType.Char)
                  
            //};
            //parm[0].Value = 3;
            //parm[1].Value = "aaa";
            //parm[2].Value = "bbb";
            //parm[3].Value = '1';
            OracleHelper.ExecuteNonQuery(OracleHelper.ConnectionString, CommandType.Text, SQL_ADMIN_INSERT_INTO, parm);
            
        }
底层用的是微软的PETSHOP4.0的OracleHelper.cs类,用的VS2005+ORACLE 9i
报一个ORA-01036错
SQL语句经过了测试 没有问题 估计是参数的问题 也就是出在parm身上
请帮忙解决下,分不够还可以加分