Queries on cron and GUI login...

I have 2 queries:
1.how do we monitor failed GUI logins...? I think the /var/adm/loginlog will log
only failed logins happened at /dev/console and virtual terminals..
2.How to use cron scheduler to display a message when a user is working in GUI Terminal window irrespective of in which terminal he is working..? Also, is there any tool to provide a popup message via cron scheduler while a user is in GUI mode?

Thank u..

1. /var/adm/loginlog only logs a login failure after a number of attempts, BSM auditing is better, take a look at the auditing section of:
   Solaris Security Guide

2. xmessage can be used to provide pop-up messages to a user using a GUI and can be obtained from http://www.sunfreeware.com, that would be simpler than inserting a message into an active terminal window.