unable to set QLPreviewController title for list of Files

Question

Everytime i pass a list of files to QLPreviewController its title shows "1 of 100" , "2 of 100" etc. Even when i have passed the file name to its QLPreviewitem's property "previewItemTitle" in its delegate method "previewItemAtIndex".

- (id <QLPreviewItem>) previewController: (QLPreviewController *)     controller previewItemAtIndex: (NSInteger) index
{
 BasicPreviewItem* item = [[[BasicPreviewItem alloc] init]   autorelease];
item.previewItemTitle = m_Name;
item.previewItemURL = [NSURL fileURLWithPath:[NSString  stringWithFormat:@"%@",iFilePath]];
return item;
}

or even if Added

 self.title = iDocument.m_Name;

in above method. What i need it it should set change title everytime i swipe through list of files passed.