Re: restrict modification to all the fields in service call after close status is selected
I think that you are looking for the Status Entitlement feature.
With this you can refine user access capabilities by providing the means to limit user access to only a specified range of statuses and then users will only be able to modify those items that are in the statuses their entitlements permit.
Status entitlements are set through the items tab of the Roles screen; access granted to role items can further refined so that the user can only have the access rights to view, modify, and delete items in a certain status, or within a specified range of statuses.
Check the SD client's online help, look for status entitlement, it will show you how to configure it.