it is possible to set a button on your page that will indicate when the admin is online... like all other live-support scripts, vbulletin store the sessions in the database and is aware when an admin is visiting the site... so it would be easy to code a condition to show the button when the admin is on... sure!
What nexialys said is exactly what I am wanting to do. I am sure it wouldn't be too hard to do. I just don't know how. Sorry if my question wasn't clear.