Help with matching two fields to have same value

I'm a bit of a novice to all this suite script stuff, so any help would be most appreciated.

Here's the scenario:

I have a field on a phone call form that when the form is saved/submitted, that field value will map back to a field on the customer form.

The fields are both list type fields, and they have the same values available. My goal was to have an afterSubmit function update the customer form. Below is the code that I've come up with after searching what others have done and trying to decipher the developers guide.

   function afterSubmit(type)    {   nlapiGetFieldValue('custevent_acct_health_phone_field')   nlapiSubmitField(customlist, 31, 'custentity_account_health','yellow' 'red' 'green' )    }