thanks Namish for your reply,
but this is not the solution I want, as per your solution

if [[ $str2 -eq 13 ]]

now in future if I want to change 13 to 15 then I have make changes in the code.
and I dont want to cahnge in the code.
I want my script capable of taking this time from some where outside this script.
I hope you got my problem.

Regards
Manvar