searchbar displaycontroller getting the data from server but displaying complete fake already displayed data

Question

- (void) searchBarSearchButtonClicked:(UISearchBar *)theSearchBar
{
    isSearching = YES;

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSInteger conf=[[[NSUserDefaults standardUserDefaults] objectForKey:@"Deepak_ConfId"] intValue];
    NSInteger PersonId = [[defaults objectForKey:@"DEEpak_UserId"] intValue];

    //Service method
    [dataService GetAllPresentationsv2:conf Date:@"" TrackID:@"-1" Tittle:presentationtitleStr Location:@"" Speaker:@"" Keyword:@"" Moderator:@"" PersonID:PersonId tTTypeId:CategorieId];
}

-(BOOL)searchDisplayController:(UISearchDisplayController *)controller
    shouldReloadTableForSearchString:(NSString *)searchString
{
    presentationtitleStr = [searchString copy];
    return YES;
}

enter code herei am getting the data when search checked in the complete array.But displaying fake alredy displayed data when scroll that time crash and beyod bounds when i clicked on clear default searchbar button it displaying the data what is the problem i dont geeting please help me...