private String chooseFolder() {
IProject project = MuClipsePlugin.getProject(txtProject.getText().trim());
final ElementTreeSelectionDialog dialog =
new ElementTreeSelectionDialog(getShell(),
new FileLabelProvider(),
new FileTreeContentProvider(true));
dialog.setAllowMultiple(false);
dialog.setTitle("MuClipse");
dialog.setMessage("Select a folder");
dialog.setInput(project);
dialog.setValidator(new TypedElementSelectionValidator(