exit codes on custom scripts

Hi,

I found this link (http://www.manageengine.com/products/desktop-central/returning-error-code-on-scripts-how-to.html) while doing research on custom scritps. How does the exit codes help? Does Desktop Central tell me if there is an error while running the custom script? How will it let me know, i.e. will it send an email? Let me know if you need more details. Thanks.