Within Zoho CRM, each module has a 'system' name associated with it. Zoho allows you to change your Module Label, but the system name remains the same. When you create a custom module in Zoho CRM, the system automatically assigns the Custom Module a system name, with the naming Convention "CustomModuleX", where X is the next number in an internal counter. So, for example, the 4th custom module you create will be known internally as CustomModule4.
Why am I telling you this? Because when you are writing custom functions, you must use the system Module name to retrieve and update records. You can find this system name in the module list as shown below: (Setup->Modules)