Initializing variables when the Back key is pressed

Sub hc_ResponseSuccess (Response As HttpResponse, TaskId As Int)
   Dim res As String
   res = Response.GetString("UTF8")
   Dim parser As JSONParser
   parser.Initialize(res)
   Select TaskId
      Case Common.SEARCH_RESULTS
         ressulset = parser.NextArray
         If ressulset.Size = 0 Then
            StartActivity(NoResults)
         Else
            StartActivity(ResultsActivity)
         End If
   End Select
   Response.Release
End Sub

Sub Globals
   Dim ResultsPanel As Panel
   Dim lvResults As ListView
End Sub

Sub Activity_Create(FirstTime As Boolean)
   If FirstTime Then
      ResultsPanel.Initialize("ResultsPanel")
      ResultsPanel.LoadLayout("results")
      Activity.AddView(ResultsPanel, 0, 0, 100%x, 100%y)
   End If
   
   For i = 0 To Search.ressulset.Size - 1
      Dim m As Map
      m = Search.ressulset.Get(i)
      Dim tl As ThreeLines
      tl.First = m.Get("Name")
      tl.Second = m.Get("Cost")
      tl.Third = m.Get("SID")
      lvResults.AddTwoLines2(tl.First, "Rs. " & tl.Second & " per km", tl) 'the error occurs here
   Next
   ProgressDialogHide
End Sub