LongListSelector Load items Infinite - windows-phone-8

Question

For my windows phone 8 app, my data provider provides 10 items per page and i have to show the results in a LongListSelector.
My first challenge is that it provides data in JSON that i parse to array, so i cannot easily add items in my longlistselector.ItemsSource. Well, will do it somehow by observableCollection.
Second challenge is when user scrolls down to 8th or 9th item i have to load page 2 and so on until it returns items less than 10.
I am done with ItemRealized event, it is called for all 10 items at load so if i load page 2 it will load all the pages before screen loading.
I have checked the TwitterSearch example msdn has but unfortunately its api is expired. Any help?
EDIT
For my test projects, item template is below.
<phone:LongListSelector.ItemTemplate>
<DataTemplate >
<ListBoxItem Margin="20">
<TextBlock FlowDirection="LeftToRight" Text="{Binding}" Margin="0,10,0,0" Foreground="#343330" FontSize="24"/>
</ListBoxItem>
</DataTemplate>
</phone:LongListSelector.ItemTemplate>
and the binding is below.
ObservableCollection<string> data = new ObservableCollection<string>();
.
.
.
IsLoading = true;
for (int i = 0; i < 10; i++)
data.Add(string.Format("item {0}", (pageNo * 10) + (i + 1)));
pageNo++;
IsLoading = false;
itemRealized event is given below
private void LongListSelector_ItemRealized(object sender, ItemRealizationEventArgs e)
{
//data.ItemCount = data.ItemCount + 1;
itemCount++;
if (itemCount < 100
&& reloadOnItem.Contains(itemCount))
{
loadData();
}
}