Can I Change Jump Height Depending On Length Of Button Press?

Hello everyone,
I’ve recently started using flowlab due to my laptop breaking, meaning I can only use my Chromebook. This made me decide to check out flowlab and see what I could develop on it.

I’ve been putting together a simple little platformer but I’ve come across a problem. In most mainstream platformers (all the way back to the original Super Mario Bros. on the NES) you can change the height of your jump by changing how long you hold down the jump button. Is there any way to code this into my flowlab game? Thanks in advance!

Yeah, I made a example that demonstrates 3 types of jump including the Hold.
There are different version of the hold with slightly more complexity.

Jump Meter Examples:
http://flowlab.io/game/play/1186457