For your version of the wwmysqldump script, you should change the second line to
HOME=/home/wwadmin
(assuming that that is the correct home directory for wwadmin), then it should be able to dump the database without a password. The way you have it now, it will dump it to the screen. Once you have this working you can change the third line to
mysqldump --opt webwork > /home/wwadmin/downloads
(assuming /home/wwadmin/backups is where you want the backups to go).