SQLException: No suitable driver found for jdbc:derby

I've got this exception after running my project
Really don't know what to do!
SQLException: No suitable driver found for jdbc:derby://localhost:1527
I've add derbyclient.jar to Library.but I didn't get any different result.I also don't want to create a new database.
I wasn't able to attach it here but here are two links to download project files.
source:
http://bia2internet.com/dl/java/java.zip
database:
http://bia2internet.com/dl/java/db.zip