Custom record list in entity form

Hi,

I'm a relative beginner with Netsuite but I'm stuck on something that i think should be quite simple.

I have a custom record to represent various pieces of computer hardware (assets).

Each asset should be associated with a customer and each customer can have 0,1 or many assets.

I what to display a customers assets in a list in a subtab of the customer record however all i have managed to achieve is to display all of a customers assets in a dropdownlist.

Any hints?

Please let me know if more clarity is required.