Use the menu.
MENU
Search For...
Service Search - choose your service to search
(or)
Custom Search
To program the Custom Search
MENU
Search For...
Edit Custom
Use the Hold/Resume button only for stopping and restarting the search. If you hit Scan, it will cancel the search and resume scanning.
If you have ProScan, you can assign a Quick Key to each Custom or Service Search and then they can be brought up much easier. You can also use the Scan button to resume searching. I have not found this option available in the hand programming menu.
chris