各位路过的高手请给小弟多多帮助，
我是刚学的C#，
我用SQL建立了一个名为webdevelop的数据库，其中有表loginuser

我在MyClass.cs这个类里写了
private static string connString="Server=localhost;uid=sa;pwd=;database=webdevelop";

        public static string ConnString
        {
            get
            {
                return connString;
            }
                    }
然后在main.aspx中的buttonOK这个按扭中写入
{
            string name=this.TextBoxName.Text;
            string pwd=this.TextBoxPassword.Text;
            if(name.IndexOf("'")>-1    || name.IndexOf(' ')>-1    || name.IndexOf('"')>-1
                || pwd.IndexOf("'")>-1 || pwd.IndexOf(' ')>-1 || pwd.IndexOf('"')>-1)
            {
                this.TextBoxState.Text="用户名或密码包含有非法字符！";
                return;
            }
            SqlConnection conn = new SqlConnection(MyClass.ConnString);
            string sqlstr="select * from loginuser where (username='"+name+"') and ("
                +"userpwd='"+pwd+"')";
            SqlCommand command = new SqlCommand(sqlstr,conn);
            conn.Open();
            try
            {
                SqlDataReader dr=command.ExecuteReader();
                if(dr.Read()==true)
                {
                    SetEnable(true);
                    Session["userName"]=name;
                    this.TextBoxState.Text="用户"+name+"登录成功。";
                }
                else
                {
                    SetEnable(false);
                    Session["userName"]="";
                    this.TextBoxState.Text="登录失败，无此用户或密码不正确！";
                }
                dr.Close();
            }
            catch(Exception err)
            {
                this.TextBoxState.Text="系统错误："+err.Message;
            }
            conn.Close();
        }
但是我在运行的时候，点了按扭就出现错误了！
那为高手帮帮忙，感觉不尽！