Thanks for ur reply.
After doing lot of things,i taken the image.
First,i created one partition(sda9) on my hard disk which is planning to take the image.Formatted with ext3,and labelled that as clonezilla.I extracted the clonezilla live on to that.And entered the partition details in fstab to mount that partition automatically at boot time on /mnt.In grub,i entered the script to boot from 9th partition which i have created previously(sda9).
Finally,after reboot,i got the grub menu with two options,one for linux kernel and other clonezilla.Selected clonezilla,and gone forward with the asked questions,finally it will ask to select the disk/partition to take the image and destination to store that.
After 10 minutes,i got my entire system image.Now i have to move that image safely onto a dvd or flash drive to use when my system crashes.
This is solved........
Why i have not used cd is.. by using that we can do the process,but i just tried to explore the process in alternative way.