http://localhost:8099 does not work

hi everyone,
i'm a student from italy and recently i installed pentaho ce,after i searched on internet how to start the biserver and the indications was to open the terminal(i'm working on mac osx 10.10.1 with java 1.8) and in the directory biserver-ce launch the command ./start-pentaho.sh and after that open the administration console through a web browser(firefox for me) and typing http://localhost:8099 and logon with the default credential,but the connection fail and nothing appear.

Please can someone help me to solve it because i have a homework to release.Thanks