ScriptRunner, Issues with required custom field based on another field value

[Brooke Anglin]

Below is the script I have. Both fields are on the create screen but when I add the behavior and run a test nothing happens.

import com.onresolve.jira.groovy.user.FieldBehaviours
import groovy.transform.BaseScript

@BaseScript FieldBehaviours fieldBehaviours

def SegmentField = getFieldById("customfield_12015")
def MerchantOwnerAreaField = getFieldById("customefield_13601")

String SegmentIssueValue = SegmentField.getValue()

if (SegmentIssueValue == "Merchant") {
    MerchantOwnerAreaField.setRequired(true)
} else {
    MerchantOwnerAreaField.setRequired(false)
}

when I run it in the script console it gives me the following error Cannot get property 'customfield_12015' on null object

I am new to all of this... can anyone tell me more about the import piece at the top? I feel that is why I am getting the error.

 Any help would be greatly appreciated!!!

[Mark Markov · Accepted solution]

Hello @Brooke Anglin

Where did you place your script? This script in your behaviour must be attached to your customfield_12015. See screen bellow 

[Brooke Anglin]

this worked !! thank you

[Mark Markov]

You re welcome! If this helps you please mark answer as accepted :)