public Object execute(ExecutionEvent event) throws ExecutionException {
IProject project = getProject(event);
RepositoryProvider provider = RepositoryProvider.getProvider(project);
if (provider instanceof CVSTeamProvider) {
CVSImporterWizard wizard = new CVSImporterWizard(project);
Shell activeShell = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getShell();
WizardDialog wizardDialog = new WizardDialog(activeShell, wizard);
wizardDialog.open();
} else if (provider instanceof SVNTeamProvider) {
SVNImporterWizard wizard = new SVNImporterWizard(project);