[RESOLVED] Converting Frames-per-second to Timer Interval

[iMiles]

I have an animation program which allows users to import and animate images. I do this using timer events. I have a listbox which contains the image references, and a Image which displays the chosen image. Here is the code:

When the user clicks the "Animate" button:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles animate.Click
        Dim cananimate As Boolean = True
 
        'The secret code
        If Images.Items.Count > 0 Then
            Images.SelectedIndex = 0
 
            'While it has a image in front, keep animating
            If Not Images.SelectedIndex = Images.Items.Count - 1 Then
 
                Timer1.Start()
 
                'If only one image present, display a message
                If Images.Items.Count = 1 Then
                    MessageBox.Show("You must have more than one image to begin animating.")
                End If
            End If
        End If
    End Sub

Timer tick event:

Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        If Not Images.SelectedIndex = Images.Items.Count - 1 Then
            Cursor = Cursors.AppStarting
            Images.SelectedIndex += 1
            mainimage.Refresh()
            Cursor = Cursors.Default
            If Images.SelectedIndex + 1 = Images.Items.Count Then
                Timer1.Enabled = False
            End If
        End If
    End Sub

I want to make a dialog to appear and allow the user to select a custom FPS for the animation. For instance, if they type 15, the listbox must go down 15 images in 1 second. But how do I convert FPS to a timer interval?