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Kode 

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.Security.Cryptography;
using MySql.Data;

namespace WindowsFormsApplication1
{

        public partial class Form1 : Form
        {
            public Form1()
            {
                InitializeComponent();
            }

            static string getMd5Hash(string input)
            {
                MD5 md5 = System.Security.Cryptography.MD5.Create();
                byte[] inputBytes = System.Text.Encoding.ASCII.GetBytes(input);
                byte[] hash = md5.ComputeHash(inputBytes);

                StringBuilder sb = new StringBuilder();
                for (int i = 0; i < hash.Length; i++)
                {
                    sb.Append(hash[i].ToString("X2"));
                }
                return sb.ToString();
            }
            private void button1_Click(object sender, EventArgs e)
            {
                int val1 = textBox1.MaxLength;
                int val2 = textBox2.MaxLength;
                string input = textBox2.Text;
                if (val1 != 0 && val2 != 0 && input != "")
                {
                    input = getMd5Hash(input);
                    LoadGuests(val1, val2, input);
                }
            }

            public void LoadGuests(int valen1, int valen2, string input)
            {
                try
                {
                    //create a new mysqlconnection
                    MySqlConnection mycon = new MySqlConnection("datasource=Ipadresse;username=usernamet;password=Passwordet;database=Databasen");
                    //create a mysql DataAdapter
                    MySqlDataAdapter myadp = new MySqlDataAdapter("SELECT * FROM users WHERE Nick=" + textBox1.Text + " AND Pass=" + input + "", mycon);
                    //create a dataset
                    DataSet myds = new DataSet();
                    //now fill and bind the DataGrid
                    myadp.Fill(myds, "users");
                    dataGrid1.DataSource = myds.Tables["users"].DefaultView;
                    dataGrid1.SetDataBinding(myds, "users");
                }
                catch (MySqlException ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
        }
}

Kode 

Error	1	The type or namespace name 'MySqlConnection' could not be found (are you missing a using directive or an assembly reference?)	C:\Documents and Settings\mig\My Documents\Visual Studio 2008\Projects\SQL Login123\SQL Login123\Form1.cs	52	21	SQL Login123
Error	2	The type or namespace name 'MySqlConnection' could not be found (are you missing a using directive or an assembly reference?)	C:\Documents and Settings\mig\My Documents\Visual Studio 2008\Projects\SQL Login123\SQL Login123\Form1.cs	52	49	SQL Login123
Error	3	The type or namespace name 'MySqlDataAdapter' could not be found (are you missing a using directive or an assembly reference?)	C:\Documents and Settings\mig\My Documents\Visual Studio 2008\Projects\SQL Login123\SQL Login123\Form1.cs	54	21	SQL Login123
Error	4	The type or namespace name 'MySqlDataAdapter' could not be found (are you missing a using directive or an assembly reference?)	C:\Documents and Settings\mig\My Documents\Visual Studio 2008\Projects\SQL Login123\SQL Login123\Form1.cs	54	50	SQL Login123
Error	5	'System.Windows.Forms.DataGridView' does not contain a definition for 'SetDataBinding' and no extension method 'SetDataBinding' accepting a first argument of type 'System.Windows.Forms.DataGridView' could be found (are you missing a using directive or an assembly reference?)	C:\Documents and Settings\mig\My Documents\Visual Studio 2008\Projects\SQL Login123\SQL Login123\Form1.cs	60	31	SQL Login123
Error	6	The type or namespace name 'MySqlException' could not be found (are you missing a using directive or an assembly reference?)	C:\Documents and Settings\mig\My Documents\Visual Studio 2008\Projects\SQL Login123\SQL Login123\Form1.cs	62	24	SQL Login123