Before you call methods oSplitApp.setInitialDetail("detail1"), oSplitApp.setInitialMaster("master1"),
You need to add master and detail pages to SplitApp.
Do this
//add the master pages to the splitapp control
oSplitApp.addMasterPage(oMasterPage1);
//add the detail pages to the splitapp control
oSplitApp.addDetailPage(oDetailPage1);