Thanks dekchidriver bro for the reply
Now i can access internet on my laptop using ethernet only through my eth0 interface editing /etc/Network/interfaces as
auto eth0
iface eth0 inet dhcp

and tried similar kind of command for my wlan0 interface too but didnt work

my network adaptor atheros communication AR9285 wireless adaptor
ethernet controller is Marvell Technology  88E8059 PCI
I m using Netgear CGD24G as my access point

Then i followed the instructions as specified by this link to install the driver
http://www.cyberciti.biz/faq/marvell-88w8335-chipset-netgear-wg311-pcicard-driver/

can u share me the steps how u configured the wireless network