Replace Field Contents could have disasterous results here. This step can modify the value of the field specified in it for every record in your table.
I'd define the name field to auto-enter either the current username or the current Accountname each time a new record in Who Modify is created. A second date or timestamp field can also be set to auto-enter the current time or timestamp when the record is created. This way all the script does is create the new record and the needed info is automatically entered. You select auto-enter field options for a field in manage | database | fields.
I'd also create the new record in "Who Modify" before performing the find. That way this information is collected automatically before the user has any chance to quit and keep this info from being logged.