dissable item master

i want to hide or dissable item master and customer master for a particular user.

Only for one particular user of Navision 5.0 i want to dissable custumar master and item master not for all other user.

how could i do this.

should i have to do some codding.

please explain this it is very important.

and also give the required solution

There are 2 standard Roles

  1. S&R-CUSTOMER Read customers and entries

  2. S&R-CUSTOMER, EDIT Read customers and entries

Assign these roles to appropriate users.