ZOHO CRM - Deluge & Script Client

ZOHO CRM - Deluge & Script Client

Good morning everyone, 

I've a couple of questions about deluge scripts and script client.

1) How can I set - via client script - a rule that set a defined length for a specific field? Let's say i want a field A to be 11-digits length.

2) How can i set a field as mandatory? Always in client script.

Thank you