Dynamic stamp not picking up identity name

I've created a custom stamp with the word PREPARED and two fields, one for identity name and one for date.  No matter what I have tried, it is not filling in my name, and I have checked Preferences to make sure my name is present.  This is my script:

event.value = "by " + ((!

identity.name | |

identity.loginName !=

(event.source.source | |

this).Collab.user) ?

(event.source.source | |

this).Collab.user :

identity.name)

 + " at " + event.value;

I am using Acrobat Pro DC 2015, and I am only previewing the form right now, until it's ready to copy into the stamps folder.