private void UpdatePages()
{
updatePaging = true;
if (pageSelectionUntil == 0 | AllPages)
{
PageSelectionUntil = maxPages;
}
if (pageSelectionFrom > pageSelectionUntil | pageSelectionFrom > Maximum)
PageSelectionFrom = 1;
if (pageSelectionUntil > maxPages)
PageSelectionUntil = maxPages;
updatePaging = false;
NotifyPropertyChanged("Maximum");
NotifyPropertyChanged("PageSelectionFrom");
NotifyPropertyChanged("PageSelectionUntil");
}