Lock Fields

So, I am trying to add a couple of fields as a new section in the Cases Module in SugarmCRM. 

I am trying to make the fields read-only after a User has filled in one of the fields, to prevent anyone to go back and edit it. Field level permissions will restrict access but I want users to have access to it but lock access after the fields have been filled. 

I read somewhere that a Workflow could be created for that

Hi Haritha,

To make sure I understand you clearly, do you want to restrict this for set of users or everyone including admin? If there is a value already in the field no one should edit it? If so who will enter the initial value into the field? Can you please clarify?

Hi Haritha,

To make sure I understand you clearly, do you want to restrict this for set of users or everyone including admin? If there is a value already in the field no one should edit it? If so who will enter the initial value into the field? Can you please clarify?