While you can do that, it would be easier to perform a find or constrain your found set to omit the records with this value in the first place.
This is a fairly simple thing to set up and faster to do as well.
Here's the specific answer to your question now that I've told you there's a better way:
Go To Reord/Request/Page [First]
If [YourTable::Sample = "Yes" ]
Go To Record/Request/page [next ; exit after last]
The better way is a script along these lines:
Enter Find mode
Set field [YourTable::Sample ; "No"]
Set Error Capture [on]
Constrain Found set
Thanks for the second option. I am working with FM Pro v.6 and don't see the "Constrain Found Set " option listed in the script writer. I'm guessing it's something included in a newer version...or I am just blind. LOL The first script you provided works great. Thanks again.
And that's what happens when you don't identify the version that you are using. There've been a lot changes since the release of version 6.
You may be able to use this script depending on your database design:
Enter Find Mode 
Set Field [Yorutable::YourField ; Yourcriteria here]
#use as many set field steps as you need to spell out the find criteria needed
Set Field [YourTable::Sample ; "No"]
Set Error capture [on]
Perform Find 
One way to script such finds is to give the users global fields where they can enter their find criteria, then use set field while in find mode to set up the needed find request(s) and then perform the find.