Hiding Options Based on Individual Worksheet Completion

[jetlag]

I have developed a 360 Degree Feedback Instrument that can be completed by a participant and then forwarded to 4 other people to fill in.

I have a "Front Page" which has hyperlinks to various worksheets, where each person fills in the details.

When the worksheet has been completed, I send (Hyperlink) them back to the "Front Page" to save and return the spreadsheet.

I would like to check if a page has been completed and then deny access to that page or pages, in order to guard the privacy of the individuals and deny the participant the opportunity to change the results.

Any suggestions would be greatly appreciated.