Set a default entity on a lookup window

In case you have more entities to chose from on a lookup window, then you might want to be able to set the default for this lookup. For instance, the regarding field on an activity entity like letter, email and fax does support multiple entities. If you want this to default set to contact, then use this javascript on the form onload://set defaultcrmForm.all.regardingobjectid.defaulttype = "2";