In the CRM SDK there is an example of how to create a dublett checker. It works fine but I would like to point out a few things.

  1. Note that it is based on JavaScript, hence it will only be used when the GUI is run. When running an import, for instance, the GUI is not used and the javascript will not be run.
  2. Perhaps a lead dubletthandler should also check for the existance of an account with the same name. It is only natural to check if the new lead might already be a customer.
  3. It cannot be used offline. Users should be notfiied of this or the function to create the entity should be disabled in offline mode.

To solve the first problem, the best cause of action is to make a callout-based dublett handler in addition to the javascript based. You don’t want to throw that away since its user interface is a lot better than the callout-based checker.

Gustaf Westerlund
CRM and SharePoint Consultant

Humandata AB