Change text of ActionBar when switching tabs

Change text of ActionBar when switching tabs

I hava an ActionBar with tabs on it.
actionBar = getActionBar();
// Hide Actionbar Icon
actionBar.setDisplayShowHomeEnabled(false);
actionBar.setDisplayShowTitleEnabled(true);
// Create Actionbar Tabs
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create first Tab
tab = actionBar.newTab().setTabListener(new BusinessActivity());
// Create your own custom icon
// tab.setIcon(R.drawable.business);
tab.setText("Business");
actionBar.addTab(tab);
The BusinessActivity class in my example is extends Fragment.
How can i change the ActionBar title when switching tabs?
Thanks.