Setting issue security level based on custom field value using a scriptrunner listener

[Sysad]

Hi Community

I'm trying to set issue security level based on the custom field when issue created and when custom field is updated. Here is my code and am not sure where to go from here. Any help is appreciated.

import com.atlassian.jira.issue.Issue
import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.issue.security.IssueSecurityLevelManager
import com.atlassian.jira.issue.security.IssueSecuritySchemeManager
import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.issue.security.IssueSecurityLevel

def issueManager = ComponentAccessor.getIssueManager()
def issue = event.issue as Issue
def customFieldManager = ComponentAccessor.getCustomFieldManager()
def cf = customFieldManager.getCustomFieldObjects(issue).find {it.name == 'User County'}

if (issue.getCustomFieldValue(cf).toString().equals('County A'))
{
issue.setSecurityLevelId('10601')
}
else if (issue.getCustomFieldValue(cf).toString().equals('COunty B'))
{
issue.setSecurityLevelId('10602')
}
else// if county is empty then
{
issue.setSecurityLevelId('10603')
}