Creating internal Pop ups

A project has been handed my way to create a pop-up announcement for our
organization. The powers to be want it to be graphic like a web page, pop up
on the computers hourly. Alone with that they would also like to have a
scroll bar with a text message on each computer that can not be disabled but
staff members.

I am not sure what program to utilize for this. I was thinking FrontPage
and creating an intranet for the organization. I am not sure if that is the
best way to handle this.

Any help or ideas would be greatly appreciated.

Regards

Mary