I have this code:

```
b = str(raw_input('please enter a book '))
searchfile = open("txt.txt", "r")
for line in searchfile:
    if b in line:
        print line
        break
else:
    print 'Please try again'

```

This works for what I want to do, but I was wanting to improve on it by repeating the loop if it goes to the `else` statement. I have tried running it through a while loop but then it says `'line' is not defined`, any help would be appreciated.