how to update custome field with standard field value?

Question

Using sales force i want to update a custom field value with the value of the account name using workflow ,i have created the custom field named (Name__c) and also the workflow but i don't know what is the data i should fill the workflow with to update this value to make the account name as a unique but i could not find the exact steps i should make to perform this action

and also i have used

ISNEW() || ISCHANGED(Name) || ISBLANK(Name__c)

but i got an error message said "Error: Function ISNEW may not be used in this type of formula"

sorry as i am new in sales force technology

Answer 1

Mark the custom field named (Name__c) as UNIQUE in custom field definition.

Set the Rule Criteria : Name(standard field) not equal to null.

Evaluation Criteria : Evaluate the rule when a record is created, and any time it's edited to subsequently meet criteria

Add the field update workflow action to copy the Name to Name__c