Visit https://jalbum.net/signin and click Sign in. Sign in with your jalbum.net user name and password.
Click the tab with your user name on it to see all the albums on your account.
Find the album you want to delete and hover the mouse over its thumbnail image to make an options menu light up. To delete your album you simply click the Delete album option.
You will be asked to confirm that you want to delete your album. If you still want to delete your album click Yes, delete it otherwise click No, don't delete.