not able to upgrade to ubuntu version 13.10

[VENOLIN PRAVEEN SANTHANARAJ]

While scanning your repository information no mirror entry for the upgrade was found. This can happen if you run an internal mirror or if the mirror information is out of date.

Do you want to rewrite your 'sources.list' file anyway? If you choose 'Yes' here it will update all 'raring' to 'saucy' entries.
If you select 'No' the upgrade will cancel.
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ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: ubuntu-release-upgrader-core 1:0.192.10
ProcVersionSignature: Ubuntu 3.8.0-19.29-generic 3.8.8
Uname: Linux 3.8.0-19-generic i686
ApportVersion: 2.9.2-0ubuntu8
Architecture: i386
CrashDB: ubuntu
Date: Tue Feb 11 12:08:52 2014
InstallationDate: Installed on 2014-01-26 (15 days ago)
InstallationMedia: Lubuntu 13.04 "Raring Ringtail" - Release i386 (20130424)
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to raring on 2014-02-11 (0 days ago)
VarLogDistupgradeAptlog:
 Log time: 2014-02-11 12:05:42.410159
 Log time: 2014-02-11 12:05:46.057428
 Log time: 2014-02-11 12:08:32.604142
 Log time: 2014-02-11 12:08:52.893312
VarLogDistupgradeTermlog:

[Brian Murray (brian-murray)]

You only have a cdrom entry in your sources.list file subsequently the upgrade fails. You need to add an ubuntu mirror to your /etc/apt/sources.list file for the upgrade to proceed and to be able to update your system with new versions of packages.