C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using MySql.Data.MySqlClient;
namespace ExampleOne
{
    public partial class login : Form
    {
        public MySqlDataAdapter da;
        public DataSet adset;
        public string g_login;
        public login()
        {
                        
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void textBox2_TextChanged(object sender, EventArgs e)
        {

        }

        
        private void btnlogin_Click(object sender, EventArgs e)
       {
            string g_login = this.tbUsername.Text;
            string g_password = this.tbpassword.Text;
            string MyConString = "server=localhost;database=password;uid=root;password=asd";
            MySqlConnection connection = new MySqlConnection(MyConString);
            string Strsql = "select * from tablogin where ='"+g_login ;
           
           try
            {
                connection.Open();
                MySqlDataAdapter DA = new MySqlDataAdapter(Strsql, connection);
                MySqlCommandBuilder cmdb = new MySqlCommandBuilder(da);
                DA.Fill(adset, "tablogin");
                DataColumn[] key = new DataColumn[1];
                key[0] = adset.Tables["tablogin"].Columns["password"];
                adset.Tables["tablogin"].PrimaryKey = key;
                DataRow dr = adset.Tables["tablogin"].Rows.Find(g_password);

                if ((g_login == dr["userid"].ToString()) && (g_password == dr["password"].ToString()))
                {
                    MessageBox.Show("You are logged in!","welcome",MessageBoxButtons.OK,MessageBoxIcon.Information);
                }                              
                 else
                    {
                        MessageBox.Show("You entered wrong Username or Password","Warning",MessageBoxButtons.OKCancel,MessageBoxIcon.Warning);
                    }              
                
           }
            catch (Exception ex)
            {
                Console.WriteLine("Error Conecting to database", "window information" + ex.Message.ToString(),
                MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }

        private void Close_Click(object sender, EventArgs e)
        {
            DialogResult dr = MessageBox.Show("Are you sure to Exit ?","finish" ,MessageBoxButtons.YesNo, MessageBoxIcon.Question);
            if (dr == DialogResult.Yes)
            {

                Application.Exit();
            }
        }
    }
}