Send to Friend - Keep the message after Send

Can someone tell me how to stop the message in “Send to Friend” from being cleared when the email is sent?

When people want to send the same message to a number of people they have to type it in from scratch. They can't easily use copy / paste as they are copying and pasting email addresses.

Not sure if I should be putting the value of the message into a variable and reading it back when I load the form, nor exactly where I should be doing that. I have tried in send_to_friend.tpl & the corresponding mail.tpl with no luck, but my smarty skills are very limited.

Any help appreciated.