Saving empty feedback 'hangs' the div and displays 'Message field is required.' on next page.

If you click the save button before typing anything in the text box, the animated graphic replaces the save button, but the div holding the block does not collapse.

If you then go to *another* page, the error 'Message field is required.' displays on that unrelated page.

Could the save button be disabled until something is typed and a cancel button be added that closes the div without sending the feedback?