What you've written is not a working script, it is a handful of variable assignments and nothing further.
You need to determine how you can see the output of your first zenith command, to get it to the shell script. Once you know that, you can assign that to a variable and test the variable. You may end up needing to save it to a variable using some other means, for instance capturing the data from stdin as a user enters it.
My signature has a few BASH script references to aid you in better understanding BASH scripting. I also have a blog entry which talks about some ways to debug your scripts.
Some suggestions are to (1) remove the loop and all the following commands and just worry about the first command (2) remember that anything you can type and run from the terminal command line, you can put into a BASH script, and likewise any returns or status you get back you can save as a variable and test withing the BASH script (3) please put in some additional effort to find out how to get the desired output from your first command, I do not have or use zenith and therefore can only assess the flow of your script, which as I've said presently, does not have a flow, it is instead an infinite loop of variable definitions.
To be more effective, you may wish to review the information on good question guidelines for LQ
, as well.