Hi Ikegami, Thanks for your help. My result.txt file contains data like

host1-001 10.22.33.22
host2-001 10.33.68.254
[download]

something like above , And as i told you before I want to have update that with

host1-001 10.1.3.41
host2-001 10.1.3.42
[download]

so in your above code , where should i give the result.txt( which contains old IP as argument)...I really dont have idea. Thanks,