Can you use the submit form to simply update a row that already exists?
Bob,
A webform creates a new row but does not let you update an exisiting row. But a Row update would allow them to update an existing Row.
Here is an answer from a previous post using Google forms that may allow what you are looking for.
https://community.smartsheet.com/discussion/saving-coming-back-partially-complete-web-form
hope that helps.
Tim
Use update request to send an edtiable row to someone: http://help.smartsheet.com/customer/en/portal/articles/504779-using-update-requests