[xwiki-users] Registration validation

Hi All, I'm facing a problem with changing configuration of registration/validation method. Here is the scenario that I'm attempting to make without succes. When a new user make registration I would like that an Administrator User receive an Mail, in which, there is a link for validation the account of the user. After making this validation, the user receives an email for informing him that the validation is done and his account is accessible. What currently XWiki propose, is when a new user make registration, she/he receives an email for validating her/his new account; the validation is done by her/himself Anyone could hlep or lead me to the documentation? I would like to know if this can be by just configuation in preferences or it whether it need progmming stuffs to do. Thanks you in advances. Best regards Youcef BEY