Add group members in two ways:

Type the user names into this dialog box, separated by commas.

OR

For large numbers of users, close this dialog box. Then:

1. Create a group with no members.

2. In User Accounts, select users to be members and then select Action->Copy to Group or Mailing List.

3. Return to Groups, select the group you just created and choose Action -> Paste User(s) into Group.