Private Function CheckRect(ByVal rect As Rectangle, ByVal img As Bitmap) As _
      Boolean
        Dim l As Integer = rect.Left
        Dim t As Integer = rect.Top
        Dim w As Integer = rect.Width
        Dim h As Integer = rect.Height
        Dim lw As Integer = rect.Left + rect.Width
        Dim th As Integer = rect.Top + rect.Height
        Dim ret As Boolean = False
 
        If l >= 0 AndAlso t >= 0 AndAlso w >= 0 AndAlso h >= 0 Then
            If lw <= img.Width AndAlso th <= img.Height AndAlso rect.Left >= 0 Then
                ret = True
            Else
                ret = False
            End If
        Else
            ret = False
        End If
 
        Return ret
    End Function