import com.atlassian.jira.issue.CustomFieldManager;
import com.atlassian.jira.issue.fields.CustomField;
import com.atlassian.jira.issue.IssueManager;
import com.atlassian.jira.issue.Issue;
import com.atlassian.jira.user.ApplicationUser
import com.onresolve.jira.groovy.user.FieldBehaviours
ApplicationUser currentUser = ComponentAccessor.getJiraAuthenticationContext().getLoggedInUser();
def issueManager = ComponentAccessor.getIssueManager()
def customFieldManager = ComponentAccessor.getCustomFieldManager()
def reasonField = getFieldById("Reason Not Approved")
if (underlyingIssue.Issue.getStatus() == "Approved")
{
reasonField.setHidden(true)
}
else {
reasonField.setHidden(false)
}