I can choose only one track

hey im working with the nero sdk and my burnprogramm is allmost finished.
what im noticed know is that when i want to create an audio or mp3 cd i can only choose one track with the solution witch the sdk includes
in the sdk stand onbrowse()

CFileDialog dlgOpen(TRUE, NULL,NULL,OFN_ALLOWMULTISELECT,szFilter, this);
does anybody has an idea for this problem
at least one question do i need this funktions to burn an track because i includet them but i never start them NERO_AUDIO_ITEM_HANDLE, NERO_AUDIO_ITEM_INFO ,NERO_AUDIO_TRACK
thanx for reading and im sorry for my english i know it is not the best