Shell Programming and Scripting

I am making a shell script in linux with the bash shell. I am wondering what I can do to execute the input of a user. I am trying to get the user to enter an environment variable that already exists. Then my script will execute the value of the variable they entered.

Code:

echo "enter envir variable:"
         read Envir
         echo $Envir

When I run the program and enter an environment var like "$PATH" it just echoes "$PATH" how do I get it to execute the value of $PATH, which should be:
"bash: /usr/bin:/bin:/usr/local/bin:/usr/X11R6/bin:/usr/local/jdk/bin:/usr/local/ oracle/software/bin:"

Code:

echo "enter envir variable:"
read Envir
var=$(eval "echo \$$Envir")
echo $Envir