Error with OnClose, linking to UpdateQuery

[Ember]

Me...again. I have a form where users can enter their initials to
identify records to print. The print report prompts for the initials to
return a specific subset of records. I have an UpdateQuery which prompts for
the initials to change the value to Null. Independently these work fine,
however, when I add to the OnClose property of the report I receive: "Runtime
error '3061': Too few parameters. Expected 1."

The goal is to temporarialy store the users initials so that only the
records they wanted to print are printed and after they are printed to clear
their initials from the underlying table.

Here is my code for the OnClose property:
Private Sub Report_Close()
CurrentDb().Execute "qryPortPrint", dbFailOnError
End Sub

Here is my code for the qryPortPrint:
UPDATE tblFiles SET tblFiles.Print = Null
WHERE (((tblFiles.Print) Like [Enter Initials]) AND
((tblFiles.Portfolio)=Yes));

Any ideas would be welcomed!
Thanks!
Ember