vb.net How to backup database file in a specific location

Public Class frmbackup
    Dim a, b As String

    Private Sub frmbackup_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        txtpath.ReadOnly = True
        a = Application.StartupPath
    End Sub


    Private Sub btnbkup_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnbkup.Click
        Try
            If txtpath.Text = "" Then
                MsgBox("Please select path", MsgBoxStyle.Information, "Backup error")
            Else

                b = txtpath.Text
                FileCopy(a & "\data.mdb", b & "\" & Date.Today & ".mdb")
                MsgBox("Bakup successfully")
            End If
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub

    Private Sub btnslt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnslt.Click
        If fbd.ShowDialog() = DialogResult.OK Then
            txtpath.Text = fbd.SelectedPath
        End If
    End Sub

End Class