[WinApi] Problem z ComboBoxem

HWND hComboBox = CreateWindowEx( WS_EX_CLIENTEDGE, "COMBOBOX", NULL, WS_CHILD | WS_VISIBLE | CBS_DROPDOWNLIST, 5, 155, 150, 300, hwnd, NULL, hInstance, NULL );
SendMessage( hComboBox, CB_ADDSTRING, 0,( LPARAM ) "1" );
SendMessage( hComboBox, CB_ADDSTRING, 0,( LPARAM ) "2" );
int index = ComboBox_GetCurSel( hComboBox );
int dlugoscCB = ComboBox_GetTextLength( hComboBox );
LPSTR TextComboBox =( LPSTR ) GlobalAlloc( GPTR, dlugoscCB + 1 );
ComboBox_GetText( hComboBox, TextComboBox, dlugoscCB + 1 );