SAP Information Steward scripting language - Rules Editor

[Wlk]

Hi,
Total beginner here, I am trying to write a simple script in SAP info steward, and I'm having a hard time finding the right resources.

I am trying to write

IF the parameter BANKS='CA'
Then BANKN should contains 7 to 12 integers ignoring special characters

Else
IF the parameter BANKS='US'
Then BANKN should contains 6-17 integers ignoring special characters

It can then close from here. Please find below for a sample of the editor.

Any help is greatly appreciated