1. Script Version: 2.5.3
2. Script Author: Nutrition35
3. Minecraft Version: 1.16.5
4. Full Code:

Code (Text):

1. on right click on enchantment table:
2.     cancel event
3.     if player's held item is sword:
4.         wait 1 tick
5.         set {Enchitem::%player%} to player's held item
6.         remove {Enchitem::%player%} from player's inventory
7.         open virtual chest inventory with size 3 named "&eSword Enchanter" to player  
8.         fillGUI(player)
9.         wait 1 tick
10.         format gui slot 11 of player with {Enchitem::%player%}
11.         format gui slot 4 of player with book named "&f&l| Daze |" with lore "" and "&7Chance to &fstun &7your &cvictim &7upon Impact!" and "&7&lRequires Level: &a᚛ 0 ᚜ &7to enchant!" and "" and "&f&lCOMMON"
12.     else:
13.         message "&cYou must hold either a &c&lSword&c, &c&lPickaxe&c, &cor &c&lArmor &cto do this!"
14.         play sound "block.note_block.pling" with volume 100 and pitch -2 to event-player
15. on inventory click:
16.     if name of event-inventory contains "&eSword Enchanter":
17.         cancel event
18.         if index of event-slot is 4:
19.             cancel event
20.             open virtual chest inventory with size 3 named "&f&lDaze Books" to player
21.             fillGUI(player)
22.             wait 1 tick
23.             format gui slot 10 of player with {Enchitem::%player%}
24.             format gui slot 12 of player with book named "&f&lDaze I" with lore "" and "&b5%% &fchance to make your victim hallucinate on attack!" and "&fHallucination lasts &b5 &fseconds!" and "" and "&fCosts &b500 Tokens!"
25.             format gui slot 14 of player with book named "&f&lDaze II" with lore "" and "&b10%% &fchance to make your victim hallucinate on attack!" and "&fHallucination lasts &b5 &fseconds!" and "" and  "&fCosts &b1000 Tokens!"
26.             format gui slot 16 of player with book named "&f&lDaze III" with lore "" and "&b15%% &fchance to make your victim hallucinate on attack!" and "&fHallucination lasts &b5 &fseconds!" and "" and "&fCosts &b1500 Tokens!"
27.             format gui slot 18 of player with red stained glass pane named "&c&lBACK"
28.     if name of event-inventory contains "&f&lDaze Books":
29.         cancel event
30.         if index of event-slot is 12:
31.             if {tokens::%player%} is greater than or equal to 500:
32.                 if lore of {Enchitem::%player%} contains "&fDaze I":
33.                     cancel event
34.                     message "&cYou already have &fDaze I &con your sword!" to event-player
35.                     play sound "block.note_block.pling" with volume 100 and pitch -2 to event-player
36.                 else:
37.                     subtract 500 from {tokens::%player%}
38.                     play sound "block.note_block.pling" with volume 100 and pitch 6 to event-player
39.                     set lore of {Enchitem::%player%} to "&fDaze I"
40.         if index of event-slot is 18:
41.             open virtual chest inventory with size 3 named "&eSword Enchanter" to player  
42.             fillGUI(player)
43.             wait 1 tick
44.             format gui slot 11 of player with {Enchitem::%player%}
45.             format gui slot 4 of player with book named "&f&l| Daze |" with lore "" and "&7Chance to &fstun &7your &cvictim"
46. on inventory close:
47.     if name of event-inventory contains "&eSword Enchanter":
48.         add {Enchitem::%player%} to player's inventory
49.     if name of event-inventory contains "&f&lDaze Books":
50.         add {Enchitem::%player%} to player's inventory

Problem being that when a person clicks on the book to change inventories to select the level of the book they want, it gives them the sword because it thinks the inventory actually closed. How can I prevent this? how can I make it so that it only gives the sword when they fully exit any GUI, or I assume thats my issue.

Thank you all.