iOS Question B4i slider

Sub Process_Globals
    Public App As Application
    Public NavControl As NavigationController
    Private Page1 As Page
    Private imageback As ImageView
    Private slider1  As Slider
    Private lbl1 As Label
End Sub

Private Sub Application_Start (Nav As NavigationController)
    NavControl = Nav
    NavControl.ToolBarVisible = True
    Page1.Initialize("Page1")
    Page1.Title = "Page 1"
    NavControl.ShowPage(Page1)
    Page1.RootPanel.LoadLayout("main")
    Page1.RootPanel.Color = Colors.Gray   

End Sub

Private Sub slider1_valuechange (value As Double)
    Dim x As Long
    x = value
    lbl1.Text = x
End Sub