nsComponentManager::CreateInstance(classID, (nsISupports *)nsnull, kIMimeContentTypeHandlerIID, (void **)&ctHandler); if (ctHandler == NULL) return NULL;
rv  = nsComponentManager::CreateInstance(classID, (nsISupports *)nsnull, kIMimeContentTypeHandlerIID, (void **) getter_AddRefs(ctHandler)); if (NS_FAILED(rv) || !ctHandler) return nsnull;
mime_locate_external_content_handler(const char *content_type,                                        contentTypeHandlerInitStruct  *ctHandlerInfo){  MimeObjectClass               *newObj = NULL;	nsCID                         classID = {0};  char                          lookupID[256];  nsIMimeContentTypeHandler     *ctHandler = NULL;  PR_snprintf(lookupID, sizeof(lookupID), "mimecth:%s", content_type);	if (nsComponentManager::ProgIDToCLSID(lookupID, &classID) != NS_OK)    return NULL;    nsComponentManager::CreateInstance(classID, (nsISupports *)nsnull, kIMimeContentTypeHandlerIID,                                      (void **)&ctHandler);  if (ctHandler == NULL)    return NULL;    if (NS_OK != ctHandler->CreateContentTypeHandlerClass(content_type, ctHandlerInfo, &newObj))    return NULL;  add_content_type_attribs(content_type, ctHandlerInfo);  return newObj;}