awk - Using bash to search for a string in the second column -

i'm trying write function looks last name (from user input) in second column , returns line user. here i've tried (and not working). importantly, when run last name in place of $input_name @ command line, works then. can see, echo confirm user input read properly. missing?

 60 last_search () {  61         echo "what last name looking for?"  62         read input_name  63         echo "$input_name"  64         awk -f':' '$2 ~ /$input_name/{print $0}' temp_phonebook  65 } 

1. use -v name=value pass shell variable awk
2. shell variable won't expanded in single quote
3. print $0 default action take out.

you can use:

awk -f: -v input_name="$input_name" '$2 ~ input_name' temp_phonebook