actually by doing so many trials and errors i am now able to connect to internet
at home using the terminal commands.... sudo pppoeconf... etc.. and then
providing username and pasword...

but i am not able to connect to internet at my office. In my office there is no
username and password. But i have a LAN connection with ip address. so i have
preset my MS Internet explorer settings in MS windows and everyday i just plugin
the internet cable/connection and my computer directly get connected to
internet.

but in ubuntu i dont know how to preset the connections, or where to inter the
ip address. I tried some thing in the connection settings but failed. I have all
the figures/data for my IP address, subnet mask, default gateway, DNS server,
Alternate DNS server and Physical Address. but dont know where to enter them to
start my internet connection.

so please help me out and let me know where to enter the details or if there is
some command to be used in terminal!