public void openLoginScreen() {
tabFolder.setSelection(new Login(tabFolder, SWT.NONE, mainScreen));
}
public Composite openClassRoomHomeControlCenter(Composite componentsAreaComposite) {
classRoomHomeControlCenter = new ClassRoomHomeControlCenter(componentsAreaComposite, SWT.NONE);
if(classRoomControlCenter != null && !classRoomControlCenter.isDisposed()) {
classRoomControlCenter.addPropertyChange(classRoomHomeControlCenter);
}