Forms on websites are a handy way to get information from your visitors. However it’s easy for a visitor to accidentally send more than one copy of a form by clicking on the form’s “submit” button more than once. The end result can be that identical emails get sent to the Webmaster, or identical records get added to a database.
This handy little tutorial shows how you can use JavaScript in your Web pages to avoid forms being submitted more than once by a visitor.