ช่วยหน่อยค่ะ ต้องการให้มัน login สู่หน้าเมนู Public Class FormLogin Private Sub FormLogin_Load

 Private Sub cmdLogin_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdLogin.Click
        If (txtUserName.Text.Trim() = "") OrElse (txtPassword.Text.Trim() = "") Then
            txtUserName.Focus()
            Exit Sub
        End If

        Dim CurrentLogin As Boolean = False
        CurrentLogin = Login(txtUserName.Text, txtPassword.Text)

        If CurrentLogin = True Then
            DBConnString.UserName = txtUserName.Text.Trim()
            frmMain.Show()
            Me.Hide()
        Else
            MessageBox.Show("UserName หรือ Password ที่คุณป้อน ไม่ถูกต้อง !!!", "ผลการทำงาน", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
            txtUserName.Text = ""
            txtUserName.Focus()
            txtPassword.Text = ""
        End If
    End Sub

    Private Function Login(ByVal _UserName As String, ByVal _Password As String) As Boolean
        sb = New StringBuilder()
        sb.Append("SELECT UserName,Password FROM UserName")
        sb.Append(" WHERE (UserName=@UserName)")
        sb.Append(" AND (Password=@Password)")
        sb.Append(" AND (IsNormal='1')")
        Dim sqlLogin As String
        sqlLogin = sb.ToString()

        Dim CurrentIV As Byte() = New Byte() {51, 52, 53, 54, 55, 56, 57, 58}
        Dim CurrentKey As Byte() = {}

        If _UserName.Length = 8 Then
            CurrentKey = Encoding.ASCII.GetBytes(_UserName)
        ElseIf _UserName.Length > 8 Then
            CurrentKey = Encoding.ASCII.GetBytes(_UserName.Substring(0, 8))
        Else
            Dim i As Integer
            Dim AddString As String = _UserName.Substring(0, 1)
            Dim TotalLoop As Integer = 8 - CInt(_UserName.Length)
            Dim tmpKey As String = _UserName

            For i = 1 To TotalLoop
                tmpKey = tmpKey & AddString
            Next

            CurrentKey = Encoding.ASCII.GetBytes(tmpKey)
        End If

        desCrypt = New DESCryptoServiceProvider
        With desCrypt
            .IV = CurrentIV
            .Key = CurrentKey
        End With

        ms = New MemoryStream
        ms.Position = 0

        cs = New CryptoStream(ms, desCrypt.CreateEncryptor, CryptoStreamMode.Write)
        Dim arrByte As Byte() = Encoding.ASCII.GetBytes(_Password)
        cs.Write(arrByte, 0, arrByte.Length)
        cs.FlushFinalBlock()
        cs.Close()

        PwdWithEncrypt = Convert.ToBase64String(ms.ToArray())

        com = New SqlCommand()
        With com
            .CommandText = sqlLogin
            .CommandType = CommandType.Text
            .Connection = Conn
            .Parameters.Clear()
            .Parameters.Add("@UserName", SqlDbType.NVarChar).Value = _UserName
            .Parameters.Add("@Password", SqlDbType.NVarChar).Value = PwdWithEncrypt
            dr = .ExecuteReader()
            If dr.HasRows Then
                dr.Close()
                Return True
            Else
                dr.Close()
                Return False
            End If
        End With
    End Functionend sub