I need to create a validation rule on two lookup fields on same custom object so that only two users A and B can change values on that field,rest other users cannot change values.
I tried the syntax i.e .AND ( ISCHANGED( Owner_Proposal__c ), $User.Username ="firstname.lastname@example.org"<> "Owner_Proposal__c ", $User.Username="email@example.com"<> "Owner_Proposal__c ") but I get a syntax error.
Please let me know the reason for syntax error.
Need your help!!