I've made some changes in the common_function.php to enable/disable functions.
-> function aGetBaseSurveyPermissions()
disable some functions. Checked and works only for the user with only the rights to make a survey the addgroup button is gone.
For an admin account this button is still active and is it possible to make a survey.
Question: How is it possible to disable some extra rights for a user?
and does someone know why the addgroup button is gone? (relation with function aGetBaseSurveyPermissions()?)