Executing a script from within a script
 

How would I execute a shell script from within another. For instance I have one script that acts as a main menu, the user picks a choice from menu and if 'x' is picked then current menu is exited and 'x' script is run. THX

I suppose you mean something like this:
-------------------
#!/bin/bash
echo 1. hello
echo 2. bye
read a
if [ $a == "1" ] ; then hello.sh ; fi
if [ $a == "2" ] ; then bye.sh ; fi

Unless the scripts are in your PATH, the above will not work and you will need to provide the path to the script.
You may also wish to have a look at the 'select' command.