设计登录数据库验证类

using System;
using System.Collections.Generic;
using System.Text;
using System.Data.SqlClient;namespace helloCsharp
{//定义验证连接数据库来验证用户合法性的类Verify
    class Verify
    {
        private string s_uid;
        private string s_pwd;
        private bool  b_flag;
        public string uid //uid属性
        {
            get
            { 
                return s_uid; 
            }
            set
            {
                if (s_uid != value)
                    s_uid = value;
            }
        }
        public string pwd//密码属性
        {
            get
            {
                return s_pwd;
            }
            set
            {
                if (s_uid != value)
                    s_pwd = value;
            }
        }
        public bool flag
        {
            get
            {
                return b_flag;
            }
        }
        //定义验证方法erify
        public bool uidVerify() {
            int i;
            SqlConnection conn = new SqlConnection("server=(local);database=DB_CFGL;User ID=sa;Password=houyichong");
            SqlCommand cmd = conn.CreateCommand("select flag from T_user where uid='"+s_uid+"' and pwd='"+s_pwd+"'");
            SqlDataReader dr =cmd.ExecuteReader();
            if (dr.Read());//如果有记录就获取权限；
            {
                if (dr["T_user"].ToString()=="1")
                b_flag = true;//Boolean.Parse(dr["flag"].ToString());
            }  
               //释放数据库资源
            cmd.Dispose();
            dr.Close();
            conn.Close();
            return b_flag;
        }            
        }    }
点击登陆按钮使用该类:
      private void btn_login_Click(object sender, EventArgs e)
        {
            Verify m_verify = new Verify();
            m_verify.uid = txt_uid.Text.ToString;
            m_verify.pwd = txt_pwd.Text.ToString;
            bool get2DB;
            get2DB = m_verify.uidVerify();
            if (get2DB)
                frmMain.show();
        }报了n多错,在线帮我搞搞啊!!!!!