How are you wanting to decide which users cannot see the new appointment? If you have Outlook/Exchange integration and the sync allows from Outlook to CRM, how will you stop the appointments from coming cross that way?

If you just wish to hard code some users in, then you can use a custom content script where if the current user ID matches one that can't use the screen, then you just redirect them to another screen.

Something like:

<script>

if(CurrentUser.user_userid == '100')

{

  if(crm.getArg("Act", crm.url()) == 362) // I think the Action code for new appointment is 362

  {

    document.location.href=(crm.url(2300));

  }

}

</script>

This is untested there might be better ways but this is what I'd start with.

Breandan

First question - are you wanting to stop users creating communications full stop? In which case look at Security Profiles

Second question - If you're wanting to remove it from the New menu (thus forcing users to go to Communications - New Task/Appointment). Then personally I would created a new field on users (e.g. checkbox called user_allownewcomms) and then in Advanced Customisation - System Menus - New Action. In the SQL field put in there user_allownewcomms = 'Y'. This then would only make the option appear if the user has the box ticked on their user account.