after saving the doc in n900 in doc folder, i did the above in xterminal and this is what it shows.

BusyBox v1.10.2 (Debian 3:1.10.2.legal-1osso26+0m5) built-in shell (ash)
Enter 'help' for a list of built-in commands.

Nokia-N900-02-8:~# dpkg -i /home/user/MyDocs/noor-yusufali-english_0.1-3_all.deb
dpkg: error processing /home/user/MyDocs/noor-yusufali-english_0.1-3_all.deb (--install):
cannot access archive: No such file or directory
Errors were encountered while processing:
/home/user/MyDocs/noor-yusufali-english_0.1-3_all.deb
Nokia-N900-02-8:~#