A comments box is just a multiline textbox and a "submit" button - the code behind defines what happens to the user input from there.
There are three main things you can do with such comments:
1) Store them for later review: a text file, or database is fine (though a DB is probably better)
2) Email the comments to a suitable person or department fro review / action / response.
3) Ignore it and junk the comment.
It's up to you and how your company works and thinks which approach to take.
DB you should have no problems with.
Email isn't difficult:
Sending an Email in C# with or without attachments: generic routine.[
^]
Ignoring comments is trivial.
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