Enabling deduplication for custom entity

If your custom entity has associated Companies or Persons, and you want to display a deduplication page when you create a Company or Person from within the context of the custom entity, do one of the following:

• To enable deduplication if the entity has Companies, open <EntityName>Company.asp and change the action from 140 to 1200.
• To enable deduplication if the entity has Persons, open <EntityName>Person.asp and change the action from 141 to 1201.

From

CRM.URL(141)+"&Key-1="+iKey_CustomEntity+"&PrevCustomURL="+List.prevURL+"&E=Accounts", 'Person', 'insert'));

To

CRM.URL(1201)+"&Key-1="+iKey_CustomEntity+"&PrevCustomURL="+List.prevURL+"&E=Accounts",  'Person', 'insert'));