How to Retrieves the link for the current record ServiceNow

var attachment_link = '';
var rec = new GlideRecord('incident');
rec.addQuery('sys_id', "dc90eab4472139100d901d98036d4320");
rec.query();
if(rec.next()){
  if(rec.hasAttachments()){
    attachment_link = gs.getProperty('glide.servlet.uri') + rec.getLink();
gs.print(attachment_link)
  }   
}