Instalation VirtualBox on Backtrak 5

Can I install VirtualBox 4.1 only in the following manner:

the first time I connect my PC to internet
My next open a new console and then use the following command:
sudo apt-get install virtualbox 4.1
and will display the following information:

root@bt:~# sudo apt-get install virtualbox-4.1
Reading package lists... Done
Building dependency tree     
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libdmraid1.0.0.rc16 python-pyicu libdebian-installer4 libecryptfs0 reiserfsprogs rdate bogl-bterm
  ecryptfs-utils libdebconfclient0 dmraid
Use 'apt-get autoremove' to remove them.
The following packages will be upgraded:
  virtualbox-4.1
1 upgraded, 0 newly installed, 0 to remove and 133 not upgraded.
Need to get 70.0MB of archives.
After this operation, 7,459kB of additional disk space will be used.
Get:1 http://download.virtualbox.org/virtualbox/debian/ lucid/contrib virtualbox-4.1 4.1.20-80170~Ubuntu~lucid [70.0MB]
Fetched 70.0MB in 33min 45s (34.6kB/s)                                                                     
Preconfiguring packages ...
(Reading database ... 341492 files and directories currently installed.)
Preparing to replace virtualbox-4.1 4.1.8-75467~Ubuntu~lucid (using .../virtualbox-4.1_4.1.20-80170~Ubuntu~lucid_i386.deb) ...
 * Stopping VirtualBox kernel modules                                                                  [ OK ]
Unpacking replacement virtualbox-4.1 ...
Processing triggers for ureadahead ...
Processing triggers for shared-mime-info ...
Unknown media type in type 'all/all'

Unknown media type in type 'all/allfiles'

Unknown media type in type 'uri/mms'

Unknown media type in type 'uri/mmst'

Unknown media type in type 'uri/mmsu'

Unknown media type in type 'uri/pnm'

Unknown media type in type 'uri/rtspt'

Unknown media type in type 'uri/rtspu'

Unknown media type in type 'fonts/package'

Unknown media type in type 'interface/x-winamp-skin'

Processing triggers for desktop-file-utils ...
Processing triggers for hicolor-icon-theme ...
Setting up virtualbox-4.1 (4.1.20-80170~Ubuntu~lucid) ...
Installing new version of config file /etc/init.d/vboxweb-service ...
Installing new version of config file /etc/init.d/vboxballoonctrl-service ...
addgroup: The group `vboxusers' already exists as a system group. Exiting.
 * Stopping VirtualBox kernel modules                                                                  [ OK ]
 * Uninstalling old VirtualBox DKMS kernel modules                                                     [ OK ]
 * Trying to register the VirtualBox kernel modules using DKMS                                         [ OK ]
 * Starting VirtualBox kernel modules                                                                  [ OK ]

Processing triggers for python-central ...
localepurge: Disk space freed in /usr/share/locale: 0 KiB
localepurge: Disk space freed in /usr/share/man: 0 KiB
localepurge: Disk space freed in /usr/share/gnome/help: 0 KiB
localepurge: Disk space freed in /usr/share/omf: 0 KiB
localepurge: Disk space freed in /usr/share/doc/kde/HTML: 0 KiB

Total disk space freed by localepurge: 0 KiB