Converting Script from RMVX Ace to RMMV?

[Mr. Open]

Hello! I was trying to make a HUD based on a simple tutorial from RPG Maker VX Ace, but I got one problem with the script used in the common event. (Source/tutorial I've used) And here's the script that I cannot convert into RMMV format:
mhp = $game_party.members[0].mhp
hp = $game_party.members[0].hp
calculate = (hp * 100) / mhp
screen.pictures[99].move(0, 10, 10, calculate, 100, 255, 0, 60)

If someone's too lazy to check the link then I'll briefly explain - This HUD was supposed to be just a health bar in the top left corner and It's made using a couple of events and common events, this script is supposed to make the health bar change according to % health value of main party member. The problem is that since it's not RMVX Ace the game cannot identify $game_party and I have no idea what should be the replacement for RMMV. (I've never used JavaScript, forgive me! )

 

[CT_Bolt]

Sounds like you could really use the following...
HUD Maker by SumRndmDde: Click Here to View

$gameParty.leader().hp

To get the first party member's hp:

$gameParty.leader().hp // current hp
$gameParty.leader().mhp // max hp

or​

$gameParty.members()[0].hp // current hp
$gameParty.members()[0].mhp // max hp

With this you could simplify your entire process.

Made a demo for you: click here to view