急求解决！！

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.OracleClient;/// <summary>
/// Dal 数据操作类
/// </summary>
public class Dal:DataBase
{
    private OracleCommand Cmd=null;
    private DataSet Ds = null;
    private DataTable Dt=null;
public Dal()
{
//
// TODO: 在此处添加构造函数逻辑
//
}
    /// <summary>
    /// 检测 用户登陆
    /// </summary>
    /// <param name="info"></param>
    /// <returns></returns>
    public DataTable CheckLogin(Info info)
    {
        
        string strOracle = "select * from [info] where I_UserName=@username and I_UserPwd=@userpwd";
        OracleParameter[] parms ={ new OracleParameter("@username",OracleType.VarChar,100),
                               new OracleParameter("@userpwd",OracleType.VarChar,200)};
        parms[0].Value = info.Name;
        parms[1].Value = info.Pwd;
        try
        {
            Cmd = ExecuteCmd(strOracle, parms);
            Dt = ExecuteDataTable(Cmd);
        }
        catch (OracleException ex)
        {
            throw new Exception(ex.Message, ex);
        }
        return Dt;
    }大家帮忙看一看，调试段程序出现：与“DataBase.ExecuteDataTable(System.Data.SqlClient.SqlCommand)”最匹配的重载方法具有一些无效参数 错误！！是怎么回事呢？？应该怎样修改呢？？