1. To Run this example, you have to have a virtual linac IOC running, which can be downloaded from 

http://www.aps.anl.gov/epics/download/examples/index.php

2. Open Virtual_Linac.opi in OPI Editor. 
3. Change the macro "user" on Display to the ${user} macro in the startup file(st.cmd) of virtual linac IOC. 
On windows, it is "win32". On Mac or linux, it is your user name. 
4. Save it and run.

