if - else script

trying to write a script that will check on user age and if their age is between 18 and 65 replies with the message that they are eligible to pay tax if younger or older they dont have to pay....

#!/bin/bash
echo " enter your age "
read age
if [ age <= 18 ]; then
echo " you do not have to pay tax "

else
if [ age > 58 & <65 ]; then # I am not sure how to use these between...
echo " you are eligible for income tax "

else
echo " you dont have to pay tax "
fi

if [[ $age -gt 58  &&  $age -lt 65 ]]; then
 <...some commands...>
 

Note the dollar sign before variable names.

Also you can use the shortcut elif instead of else if

Finally, > and < are used for string comparison; for arithmetic comparison use operators -gt , -lt , -eq , etc.