Ensuring back bet is placed before lay bet goes in

[scesc]

After watching one of Peters videos here - https://www.youtube.com/watch?v=jnO4FxSvXp8 I decided to try this on one of todays Euro 16 matches. I set it up exactly as per the video. The back bet did not get fully matched, but the lay bet was still placed into the queue. How can I ensure the lay does not go ahead, or is at least auto changed to an amount that still shows a profit, if the back bet is only partially matched ? Is this where the "place fill or kill" comes in ?

[Dallas]

This should help from the FAQ section
viewtopic.php?f=47&t=11817

[scesc]

Thanks Dallas, that explains it well