Hi Samuel, no javascript code needed.
Go to the custom field in Administration → Customisation → Order → Fields
Click on the security icon.

Add your Read / Write rules in there. (Click new and add the user or team, profile rights)

help.sagecrm.com/.../FC_UsingFieldSecurity.htm

Hi Samuel, no javascript code needed.
Go to the custom field in Administration → Customisation → Order → Fields
Click on the security icon.

Add your Read / Write rules in there. (Click new and add the user or team, profile rights)

help.sagecrm.com/.../FC_UsingFieldSecurity.htm

Hi Sean

Many thanks for your help.

This is a great feature but use with caution, the field you mentioned is a custom field so it's OK. But be careful using this on other standard fields due to the integration with Sage 200. You just need to keep in mind that the integration is generally configured to use either the Admin account or it's own account. In which case always make sure that account can edit the field (e.g. Order PO Ref) as if you were to lock it down to only certain users and forget about this it will cause the Integration to fall over

Seen this before where a customer had locked down the Opportunity Description field, ended up tripping the integration as it wants to write something into this field when it creates the auto opportunities and was unable to.