How to login throw Database.. in 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 System.Data.OleDb;
using Arbuda_Bangles.AB_DBDataSetTableAdapters;

namespace Arbuda_Bangles
{
    public partial class Form1 : Form
    {
        private OleDbConnection OleConn;
        public Form1()
        {
            InitializeComponent();
            //myCon = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=G:\\VirtueNic\\Arbuda Bangles\\Arbuda Bangles\\Arbuda Bangles\\AB_DB.accdb");
            string strconn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=G:\\VirtueNic\\Arbuda Bangles\\Arbuda Bangles\\Arbuda Bangles\\AB_DB.accdb";
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            // TODO: This line of code loads data into the 'aB_DBDataSet.User_Master' table. You can move, or remove it, as needed.
            this.user_MasterTableAdapter.Fill(this.aB_DBDataSet.User_Master);
            usertxt.Text = "";
            passtxt.Text = "";
        }
        private void butLogin_Click(object sender, EventArgs e)
        {
            //string strconn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=G:\\VirtueNic\\Arbuda Bangles\\Arbuda Bangles\\Arbuda Bangles\\AB_DB.accdb";
           // string strcmd = "select User_Master,Password from Users";
           // OleDbConnection OleConn = new OleDbConnection(strconn);
          //  OleDbCommand OleCmd = new OleDbCommand(strcmd, OleConn);
         //   OleConn.Open();
          //  // OleDbDataReader OleRead = OleCmd.ExecuteReader();
           // Welcome form = new Welcome();
          //  form.Show();
          //  OleConn.Close();

            //OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=G:\\VirtueNic\\Arbuda Bangles\\Arbuda Bangles\\Arbuda Bangles\\AB_DB.accdb");
            //OleDbCommand com = new OleDbCommand("SELECT username,password FROM User_Master", con);
            //OleDbDataReader reader;
            //bool permit = false;
            //try
            //{
              //  con.Open();
                //reader = com.ExecuteReader();
                //while (reader.Read())
                //{
                  //  if (InputName == (reader["username"].ToString()) && InputPass == reader["password"].ToString())
                   // {
                     //   permit = true;
                       // break;
                    //}
                //}
                //con.Close();
          //  }
           // catch (Exception ex)
         //   {
         //       MessageBox.Show(ex.Message);
         //   }
         //   if (permit == true)
         //       MessageBox.Show("Access granted");
         //   else
           //     MessageBox.Show("Acces denied");

          // OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=G:\\VirtueNic\\Arbuda Bangles\\Arbuda Bangles\\Arbuda Bangles\\AB_DB.accdb");
          // OleDbCommand cmd = new OleDbCommand("SELECT username,password FROM User_Master", con);
          //  OleDbDataReader read;
         //   try
         //   {
           //     cmd = new OleDbCommand("SELECT username,password FROM User_Master", con);
           //     //cmd = new OleDbCommand("SELECT username FROM User_Master WHERE password =" + Convert.ToInt32(passtxt.Text), con);
            //    if (con.State == ConnectionState.Closed)
            //        con.Open();
            //    read = cmd.ExecuteReader();
               // read.Read();//You should read only once because you can //retrieve only one record(i.e, User_Name is unique)
              //  usertxt.Text = read["username"].ToString();

               // read.Close();
               // con.Close();

        }

    }
}