What relationship did you define for this portal?
If I view my layout with the portal in Browse Mode, if its a new record, no fields appear.
With a new record, there may not be any related records linked to this new record. The new record's key field that you used to define the relationship could be empty or it could just be that there are no records in the related table that match the value in this field of your new record.
"record shows up but there is not blank line to allow adding new data"
Open Manage | Database | Relationships and double click the line between your layout's table and the portal table. Click the "Allow Creation of Records via this Relationship" check box for the Portal's table.