Select your music video file. Control-click on the file in your movies folder and select get info'. Please click on the down arrow at the bottom of the file and make sure that everything under details and ownerships and permissions is set to 'read-write'. All four sections need to be changed.
Next, log onto to Vidstore.shorelineschools.org and drop it in the period four folder.
Login as guest
Select SC Video classes.
Drop your file in the correct period.